The aging auditory system: anatomic and physiologic changes and implications for rehabilitation

Effects of aging on cortical representations of continuous speech

Understanding speech in a noisy environment is crucial in day-to-day interactions and yet becomes more challenging with age, even for healthy aging. Age-related changes in the neural mechanisms that enable speech-in-noise listening have been investigated previously; however, the extent to which age affects the timing and fidelity of encoding of target and interfering speech streams is not well understood. Using magnetoencephalography (MEG), we investigated how continuous speech is represented in auditory cortex in the presence of interfering speech in younger and older adults. Cortical representations were obtained from neural responses that time-locked to the speech envelopes with speech envelope reconstruction and temporal response functions (TRFs). TRFs showed three prominent peaks corresponding to auditory cortical processing stages: early (∼50 ms), middle (∼100 ms), and late (∼200 ms). Older adults showed exaggerated speech envelope representations compared with younger adults. Temporal analysis revealed both that the age-related exaggeration starts as early as ∼50 ms and that older adults needed a substantially longer integration time window to achieve their better reconstruction of the speech envelope. As expected, with increased speech masking envelope reconstruction for the attended talker decreased and all three TRF peaks were delayed, with aging contributing additionally to the reduction. Interestingly, for older adults the late peak was delayed, suggesting that this late peak may receive contributions from multiple sources. Together these results suggest that there are several mechanisms at play compensating for age-related temporal processing deficits at several stages but which are not able to fully reestablish unimpaired speech perception.NEW & NOTEWORTHY We observed age-related changes in cortical temporal processing of continuous speech that may be related to older adults' difficulty in understanding speech in noise. These changes occur in both timing and strength of the speech representations at different cortical processing stages and depend on both noise condition and selective attention. Critically, their dependence on noise condition changes dramatically among the early, middle, and late cortical processing stages, underscoring how aging differentially affects these stages.

Effects of Maturation and Chronological Aging on Auditory Spatial Processing: A Cross-Sectional Study Across Life Span

OBJECTIVE

The primary aim of the research was to document spatial acuity changes across the life span using a battery of psychoacoustical and perceptual tests. The secondary aim was to identify the optimal metric for measuring spatial processing changes across the life span (ages 10-70 years).

DESIGN AND STUDY SAMPLE

A cross-sectional study comprising 115 participants with clinically normal hearing was conducted. Purposive sampling was adopted to recruit participants in the study, who were divided into six groups based on their chronological age.

METHOD

Temporal, intensity, spectral, and composite correlates of spatial acuity were assessed using psychoacoustic measures and perceptual questionnaires. The temporal (interaural time difference [ITD]) and intensity correlates (interaural level difference [ILD]) of spatial perception were obtained using a MATLAB (v 2020a), whereas the composite correlate (virtual auditory space identification scores [VASIs]) and perceptual ratings of spatial processing were measured using Paradigm software and speech spatial and qualities in Kannada (SSQ-K).

RESULTS

Results across all tests (multivariate analyses variance: 6 age groups × 4 tests, followed by post hoc tests) consistently demonstrate poor ITD and ILD thresholds and overall lower spatial accuracy (VASI, SSQ-K) with increasing age. Discriminant function analyses (DFAs) revealed that VASI had a higher predictive power in capturing age-related changes in auditory spatial processing. The group segregation on spatial performance in DFA became evident after 50 years.

CONCLUSION

This study provides evidence of gradual change in all three correlates of spatial processing, with statistically demonstrable deficits appearing from fourth decade of life on VASI and fifth decade of life on binaural processing.

Adaptive Syllable Training Improves Phoneme Identification in Older Listeners with and without Hearing Loss

Acoustic-phonetic speech training mitigates confusion between consonants and improves phoneme identification in noise. A novel training paradigm addressed two principles of perceptual learning. First, training benefits are often specific to the trained material; therefore, stimulus variability was reduced by training small sets of phonetically similar consonant-vowel-consonant syllables. Second, the training is most efficient at an optimal difficulty level; accordingly, the noise level was adapted to the participant's competency. Fifty-two adults aged between sixty and ninety years with normal hearing or moderate hearing loss participated in five training sessions within two weeks. Training sets of phonetically similar syllables contained voiced and voiceless stop and fricative consonants, as well as voiced nasals and liquids. Listeners identified consonants at the onset or the coda syllable position by matching the syllables with their orthographic equivalent within a closed set of three alternative symbols. The noise level was adjusted in a staircase procedure. Pre-post-training benefits were quantified as increased accuracy and a decrease in the required signal-to-noise ratio (SNR) and analyzed with regard to the stimulus sets and the participant's hearing abilities. The adaptive training was feasible for older adults with various degrees of hearing loss. Normal-hearing listeners performed with high accuracy at lower SNR after the training. Participants with hearing loss improved consonant accuracy but still required a high SNR. Phoneme identification improved for all stimulus sets. However, syllables within a set required noticeably different SNRs. Most significant gains occurred for voiced and voiceless stop and (af)fricative consonants. The training was beneficial for difficult consonants, but the easiest to identify consonants improved most prominently. The training enabled older listeners with different capabilities to train and improve at an individual 'edge of competence'.

Mishearing as a Side Effect of Rational Language Comprehension in Noise

Language comprehension in noise can sometimes lead to mishearing, due to the noise disrupting the speech signal. Some of the difficulties in dealing with the noisy signal can be alleviated by drawing on the context – indeed, top-down predictability has shown to facilitate speech comprehension in noise. Previous studies have furthermore shown that strong reliance on the top-down predictions can lead to increased rates of mishearing, especially in older adults, which are attributed to general deficits in cognitive control in older adults. We here propose that the observed mishearing may be a simple consequence of rational language processing in noise. It should not be related to failure on the side of the older comprehenders, but instead would be predicted by rational processing accounts. To test this hypothesis, we extend earlier studies by running an online listening experiment with younger and older adults, carefully controlling the target and direct competitor in our stimuli. We show that mishearing is directly related to the perceptibility of the signal. We furthermore add an analysis of wrong responses, which shows that results are at odds with the idea that participants overly strongly rely on context in this task, as most false answers are indeed close to the speech signal, and not to the semantics of the context.

Participation restriction of adults and elderly users of an audiology clinic: association with auditory and social-environmental factors

PURPOSE

To verify the association between restrictions to auditory participation and quality of life, self-perceived health, auditory factors and sociodemographic aspects of adults and elderlies assisted in an audiology service.

METHODS

The study included 152 participants; restrictions to auditory participation were assessed using the instruments Hearing Handicap Inventory for Adults - HHIA and the Hearing Handicap Inventory for Elderly - HHIE. In order to assess the quality of life, participants answered the World Health Organization Quality of Life - abbreviated version (WHOQOL-bref). Sociodemographic characteristics were assessed using a questionnaire to characterize the participants; and by the Brazilian Criteria ABEP. The results of the hearing assessment were also collected. Descriptive, bivariate statistical analyzes (p ≤ 0.20) and multiple logistic regression (p ≤ 0.05) were performed.

RESULTS

Regarding social class, individuals belonging to classes B1 and C2 had, respectively, 4.75 and 7.73 times greater chances of presenting restrictions to auditory participation compared to individuals of class D. Regarding hearing factors, disabling hearing loss increased by 3.4 times the chance of presenting perception of restriction to auditory participation. In the environmental domain of the WHOQOL-bref instrument, each unit increased in the score was associated with a decrease of 0.96 times in the chance of perceived restriction in auditory participation.

CONCLUSION

We found that the use of the amplifying hearing aid by itself, despite its benefits, did not eliminate the restrictions on auditory participation of most participants.

Sound Generator: Analysis of the Effectiveness of Noise in the Habituation of Tinnitus

Introduction  Tinnitus is a disorder that affects 10 to 15% of de world's population. Sound therapy performed through hearing aids (HAs) with integrated sound generator (SG) is one of the forms of tinnitus treatment. Objective  To analyze the effectiveness of four masking noises in relieving tinnitus in individuals with mild and moderate bilateral sensorineural hearing loss and their influence in speech perception. Methods  The participants were 35 individuals with tinnitus and mild and moderate bilateral sensorineural hearing loss, divided into four groups. All groups underwent HA and SG adaptation, being regulated in the combined mode (HA and SG). In group 1 (G1), the white noise stimulus was applied, in group 2 (G2), pink noise was applied, in group 3 (G3), speech noise, and in group 4 (G4), the high tone was applied. All patients were subjected to the following procedures: audiological diagnosis, acuphenometry, tinnitus handicap inventory (THI), visual analogue scale (VAS), and hearing in noise test (HINT). The procedures were performed prior to and after hearing intervention, and after 3 months of use of HA and SG. Results  All groups presented a statistically significant difference for the THI, VAS, and HINT pre and postintervention. In the case of the HINT, only pink noise presented a significant difference. However, in the comparation among groups there was no significant difference. Conclusion  The present study made it possible to conclude that the four noises were equally effective in relieving tinnitus, with no statistically significant differences between the analyzed groups.

Impaired Multisensory Integration Predisposes the Elderly People to Fall: A Systematic Review

Background: This systematic review pooled all the latest data and reviewed all the relevant studies to look into the effect of multisensory integration on the balance function in the elderly.

Methods: PubMed, Web of Science and Scopus were searched to find eligible studies published prior to May 2019. The studies were limited to those published in Chinese and English language. The quality of the included studies was assessed against the Newcastle-Ottawa Scale or an 11-item checklist, as recommended by Agency for Healthcare Research and Quality (AHRQ). Any disagreement among reviewers was resolved by comparing notes and reaching a consensus.

Results: Eight hundred thirty-nine records were identified and 17 of them were included for systematic review. The result supported our assumption that multisensory integration works on balance function in the elderly. All the 17 studies were believed to be of high or moderate quality.

Conclusions: The systematic review found that the impairment of multisensory integration could predispose elderly people to fall. Accurate assessment of multisensory integration can help the elderly identify the impaired balance function and minimize the risk of fall. And our results provide a new basis for further understanding of balance maintenance mechanism. Further research is warranted to explore the change in brain areas related to multisensory integration in the elderly.

Association of Midlife Hypertension with Late-Life Hearing Loss

OBJECTIVE

To investigate the association of midlife hypertension with late-life hearing impairment.

STUDY DESIGN

Data from the Atherosclerosis Risk in Communities study, an ongoing prospective longitudinal population-based study (baseline, 1987-1989).

SETTING

Washington County, Maryland, research field site.

SUBJECTS AND METHODS

Subjects included 248 community-dwelling men and women aged 67 to 89 years in 2013. Systolic blood pressure (SBP) and diastolic blood pressure were measured at each of 5 study visits from 1987-1989 to 2013. Hypertension was defined by elevated systolic or diastolic blood pressure or antihypertensive medication use. A 4-frequency (0.5-4 kHz) better-hearing ear pure tone average in decibels hearing loss (dB HL) was calculated from pure tone audiometry measured in 2013. A cutoff of 40 dB HL was used to indicate clinically significant moderate to severe hearing impairment. Hearing thresholds at 5 frequencies (0.5-8 kHz) were also considered separately.

RESULTS

Forty-seven participants (19%) had hypertension at baseline (1987-1989), as opposed to 183 (74%) in 2013. The SBP association with late-life pure tone average differed by the time of measurement, with SBP measured at earlier visits associated with poorer hearing; the difference in pure tone average per 10-mm Hg SBP measured was 1.43 dB HL (95% CI, 0.32-2.53) at baseline versus -0.43 dB HL (95% CI, -1.41 to 0.55) in 2013. Baseline hypertension was associated with higher thresholds (poorer hearing) at 4 frequencies (1, 2, 4, 8 kHz).

CONCLUSION

Midlife SBP was associated with poorer hearing measured 25 years later. Further analysis into the longitudinal relationship between hypertension and hearing impairment is warranted.

Which Patients With a Unilateral Hearing Aid for Symmetric Sensorineural Hearing Loss Have Auditory Deprivation?

OBJECTIVES

The aim of study is to find conditions that aggravate auditory deprivation in patients with symmetric hearing loss after unilateral digital, non-linear hearing aid (HA).

METHODS

In the retrospective case-comparison study, we assessed 47 patients with symmetric sensorineural hearing loss (SNHL), wearing unilateral conventional HAs. Audiological outcomes were assessed >1 year after HA fitting (mean duration, 31.0 months). Pure-tone audiometry in HA-aided and HA-unaided conditions was performed over time. Word recognition score (WRS) was evaluated at the most comfortable listening level.

RESULTS

The initial pure tone average of four frequency thresholds at 500, 1,000, 2,000, and 4,000 Hz (PTA4) did not show a difference of >5 dB HL between HA-aided and HA-unaided ears. WRS progressively decreased for both HA-aided and HA-unaided ears although the extent of decrease was significantly greater for HA-unaided (7.6%) than for HA-aided ears (5.1%, P<0.05). Notably, auditory deprivation in HA-unaided ears was significantly greater in patients with an initial PTA4 ≥53 dB HL (P<0.001).

CONCLUSION

Bilateral HAs are strongly recommended, particularly for patients with moderate to severe SNHL to prevent auditory deprivation in the contralateral ear.

Age-Related Hearing Loss Is Accelerated by Repeated Short-Duration Loud Sound Stimulation

Both age-related hearing loss (ARHL) and noise-induced hearing loss (NIHL) may share pathophysiological mechanisms in that they are associated with excess free radical formation and cochlear blood flow reduction, leading to cochlear damage. Therefore, it is possible that short, but repeated exposures to relatively loud noise during extended time periods, like in leisure (i.e., musical devices and concerts) or occupational noise exposures, may add to cochlear aging mechanisms, having an impact on the onset and/or progression of ARHL. Consequently, the aim of the present study was to determine if repeated short-duration overexposure to a long-term noise could accelerate permanent auditory threshold shifts associated with auditory aging in an animal model of ARHL. Toward this goal, young adult, 3-month-old Wistar rats were divided into two groups: one exposed (E) and the other non-exposed (NE) to noise overstimulation. The stimulation protocol consisted of 1 h continuous white noise at 110 dB sound pressure level (SPL), 5 days a week, allowing 2 days for threshold recovery before initiating another stimulation round, until the animals reached an age of 18 months. Auditory brainstem response (ABR) recordings at 0.5, 1, 2, 4, 8, 16, and 32 kHz were performed at 3, 6, 12, and 18 months of age. The results demonstrate that in the E group there were significant increases in auditory thresholds at all tested frequencies starting already at 6 months of age, which extended at 12 and 18 months. However, in NE animals threshold shifts were not evident until 12 months, extending to 18 months of age. Threshold shifts observed in the E animals at 6 and 12 months were significantly larger than those observed in the NE group at the same ages. Threshold shifts at 6 and 12 months in E animals resembled those at 12 and 18 months in NE animals, respectively. This suggests that repeated noise overstimulation in short-duration episodes accelerates the time-course of hearing loss in this animal model of ARHL.

How Do Age and Hearing Loss Impact Spectral Envelope Perception?

Purpose

The goal was to evaluate the potential effects of increasing hearing loss and advancing age on spectral envelope perception.

Method

Spectral modulation detection was measured as a function of spectral modulation frequency from 0.5 to 8.0 cycles/octave. The spectral modulation task involved discrimination of a noise carrier (3 octaves wide from 400 to 3200 Hz) with a flat spectral envelope from a noise having a sinusoidal spectral envelope across a logarithmic audio frequency scale. Spectral modulation transfer functions (SMTFs; modulation threshold vs. modulation frequency) were computed and compared 4 listener groups: young normal hearing, older normal hearing, older with mild hearing loss, and older with moderate hearing loss. Estimates of the internal spectral contrast were obtained by computing excitation patterns.

Results

SMTFs for young listeners with normal hearing were bandpass with a minimum modulation detection threshold at 2 cycles/octave, and older listeners with normal hearing were remarkably similar to those of the young listeners. SMTFs for older listeners with mild and moderate hearing loss had a low-pass rather than a bandpass shape. Excitation patterns revealed that limited spectral resolution dictated modulation detection thresholds at high but not low spectral modulation frequencies. Even when factoring out (presumed) differences in frequency resolution among groups, the spectral envelope perception was worse for the group with moderate hearing loss than the other 3 groups.

Conclusions

The spectral envelope perception as measured by spectral modulation detection thresholds is compromised by hearing loss at higher spectral modulation frequencies, consistent with predictions of reduced spectral resolution known to accompany sensorineural hearing loss. Spectral envelope perception is not negatively impacted by advancing age at any spectral modulation frequency between 0.5 and 8.0 cycles/octave.

An Oral Combination of Vitamins A, C, E, and Mg++ Improves Auditory Thresholds in Age-Related Hearing Loss

The increasing rate of age-related hearing loss (ARHL), with its subsequent reduction in quality of life and increase in health care costs, requires new therapeutic strategies to reduce and delay its impact. The goal of this study was to determine if ARHL could be reduced in a rat model by administering a combination of antioxidant vitamins A, C, and E acting as free radical scavengers along with Mg⁺⁺, a known powerful cochlear vasodilator (ACEMg). Toward this goal, young adult, 3 month-old Wistar rats were divided into two groups: one was fed with a diet composed of regular chow (“normal diet,” ND); the other received a diet based on chow enriched in ACEMg (“enhanced diet,” ED). The ED feeding began 10 days before the noise stimulation. Auditory brainstem recordings (ABR) were performed at 0.5, 1, 2, 4, 8, 16, and 32 kHz at 3, 6–8, and 12–14 months of age. No differences were observed at 3 months of age, in both ND and ED animals. At 6–8 and 12–14 months of age there were significant increases in auditory thresholds and a reduction in the wave amplitudes at all frequencies tested, compatible with progressive development of ARHL. However, at 6–8 months threshold shifts in ED rats were significantly lower in low and medium frequencies, and wave amplitudes were significantly larger at all frequencies when compared to ND rats. In the oldest animals, differences in the threshold shift persisted, as well as in the amplitude of the wave II, suggesting a protective effect of ACEMg on auditory function during aging. These findings indicate that oral ACEMg may provide an effective adjuvant therapeutic intervention for the treatment of ARHL, delaying the progression of hearing impairment associated with age.

Age-Related Changes in Sensorimotor Temporal Binding

The causal relationship between a voluntary movement and a sensory event is crucial for experiencing agency. Sensory events must occur within a certain delay from a voluntary movement to be perceived as self-generated. Therefore, temporal sensitivity, i.e., the ability to discriminate temporal asynchronies between motor and sensory events, is important for sensorimotor binding. Moreover, differences in the physical propagation of external stimuli can sometimes challenge sensorimotor binding, generating illusory asynchrony. To overcome this problem, the brain adjusts the perceptual timing of sensory and motor events. This mechanism, named sensorimotor recalibration, helps keeping causality judgments accurate. As humans age, the broad decline in sensory and motor processing may reduce temporal sensitivity, and compromise sensorimotor recalibration. In the current study, we investigated the effect of aging on sensorimotor temporal binding by measuring changes in both temporal sensitivity and recalibration. Young and elderly adults were exposed to a prolonged physical delay between a voluntary movement (a keypress) and its perceptual consequence (a visual stimulus). Before and after this exposure, participants performed a sensorimotor temporal order judgment (TOJ) task. As expected, elderly adults showed reduced sensorimotor recalibration and sensitivity as compared to young adults, suggesting that aging affects sensorimotor temporal binding.

Age-related delay in visual and auditory evoked responses is mediated by white- and grey-matter differences

Slowing is a common feature of ageing, yet a direct relationship between neural slowing and brain atrophy is yet to be established in healthy humans. We combine magnetoencephalographic (MEG) measures of neural processing speed with magnetic resonance imaging (MRI) measures of white and grey matter in a large population-derived cohort to investigate the relationship between age-related structural differences and visual evoked field (VEF) and auditory evoked field (AEF) delay across two different tasks. Here we use a novel technique to show that VEFs exhibit a constant delay, whereas AEFs exhibit delay that accumulates over time. White-matter (WM) microstructure in the optic radiation partially mediates visual delay, suggesting increased transmission time, whereas grey matter (GM) in auditory cortex partially mediates auditory delay, suggesting less efficient local processing. Our results demonstrate that age has dissociable effects on neural processing speed, and that these effects relate to different types of brain atrophy.

Distortion product otoacoustic emissions in young adult and geriatric cats

Recordings of distortion product otoacoustic emissions (DPOAEs) were taken from 15 geriatric cats (mean age ± standard deviation, SD, 13.6 ± 2.7 years; range 10.2-19.4 years) and 12 young adult control cats (mean ± SD 4.6 ± 0.5 years; range 3.4-5 years) to identify frequency-specific age-related changes in cochlear responses. Recordings were performed for primary frequencies from 2 to 12 kHz in 2 kHz increments. Cats were considered to be geriatric > 11.9 ± 1.9 years of age. Brainstem auditory evoked response (BAER) recordings were also made for subjective comparison with DPOAE responses. No differences in DPOAE response amplitudes were observed at any tested frequency in geriatric cats compared to control cats, reflecting an apparent absence of loss of cochlear outer hair cells along the length of the cochlea. No linear regression relationships were found for DPOAE response amplitude versus age in geriatric cats, despite the progressive nature of age-related hearing loss in other species. The absence of reductions in response at any of the tested frequencies in cats within the age span where cats are considered to be geriatric indicates that age-related hearing loss, if it does develop in cats, begins later in the life span of cats than in dogs or human beings.

Auditory speed tasks as potential candidates for the study of cognitive ageing

Speed of information processing is an important cognitive ability. It facilitates the efficient operation of higher order cognitive functions, such as reasoning, and is implicated in various models of cognitive decline. The present study considers the potential benefits of expanding the measurement of processing speed to include the auditory modality. It examines the reliability and factorial structure of a variety of auditory and visual speed tasks in a sample of N = 138 older adults aged between 51 and 82 years. Our findings demonstrate that auditory measures can be used to assess processing speed as indexed by existing widely used tests of this ability. Moreover, the inclusion of auditory tasks significantly increases the relationship between processing speed and general cognitive ability. This novel research provides strong evidence of the suitability of auditory speed tasks for the study of cognitive function in older people, and demonstrates the importance of expanding cognitive measurement to include alternate modalities.

Role of antioxidants in prevention of age-related hearing loss: a review of literature

Age-related hearing loss (ARHL), also known as presbycusis, is one of the most prevalent chronic degenerative conditions. It is characterized by a decline in auditory function. ARHL is caused by the interaction of multiple factors, including cochlear aging, environment, genetic predisposition, and health comorbidities. The primary pathology of ARHL includes the hair cells loss, stria vascularis atrophy, and loss of spiral ganglion neurons as well as the changes in central auditory pathways. The research to date suggests that oxidative stress and mitochondrial DNA deletion (mtDNA) play a major role in pathophysiology of ARHL. Therefore, similar to other otological conditions, several studies have also showed that antioxidants can slow ARHL, but some also indicate that antioxidant therapy is not a magic elixir that will prevent or treat hearing loss associated with aging completely, but why? All available clinical trials, including animal and human studies, in English language that examined the protective effects of antioxidants against ARHL were reviewed. Materials were obtained by searching ELSEVIER, PubMed, Scopus, Web of knowledge, Google Scholar databases, Clinical trials, and Cochrane database of systematic reviews. Although ARHL has been shown to be slowed by supplementation with antioxidants, particularly in laboratory animals, a few studies have investigated the effect of interventions against ARHL in humans. High-quality clinical trials are needed to investigate if ARHL can be delayed or prevented in humans. However, it seems that targeting several cell-death pathways is better than targeting the only oxidative stress pathway.

Cochlear Implants in Subjects Over Age 65: Quality of Life and Audiological Outcomes

Background

Cochlear implants (CIs) have been recognized as a safe and effective means for profound hearing loss rehabilitation in children and adults and recently their use has been extended to subjects over 65 years of age. The aim of this paper was to assess indices related to changes in the quality of life (QoL) in elderly CI recipients.

Material/Methods

A case-control paradigm was used to assess the effects of CIs on the QoL. Forty-two subjects were assigned to the Case group and 15 subjects to the Control group. All 57 subjects were affected by profound hearing loss and had received a CI. Audiological data were collected from both groups at: (i) 1 month pre-implantation [T1]; (ii) 1 day pre- implantation [T2]; (iii) 30 days post-implantation, with CI used in free field [T3]; and (iv) 12 months post-implantation, with CI used in a free field [T4]. The QoL was assessed via a Glasgow Benefit Inventory (GBI) questionnaire, adapted to otolaryngology. To compare subjects across different ages with varying degrees of speech development, a perception parameter was used from the Speech Perception Categories test developed by Geers and Moog.

Results

Hearing performance was considerably improved after CI. In relation to the hearing performance at time T1, statistically significant threshold gains were observed in both groups in the T3 and T4 observation windows. At time T4, a threshold gain of 70 dB HL in the Case group and a gain of 84 dB HL in the Control group were observed. With speech therapy rehabilitation, a perception level of 6 was reached by 80.0% of patients in the Case group and by 100% of patients in the Control group. In terms of QoL, both groups showed improved post-CI scores. Statistical differences were observed between the 2 groups, with the Control group outperforming the Case group in all but the social section.

Conclusions

Despite age-related changes in auditory system and prolonged hearing deprivation, CIs offer audiological and QoL benefits in the elderly.

The Effect of Age on Listening Effort

PURPOSE

The objective of this study was to investigate the effect of age on listening effort.

METHOD

A dual-task paradigm was used to evaluate listening effort in different conditions of background noise. Sixty adults ranging in age from 20 to 77 years were included. A primary speech-recognition task and a secondary memory task were performed both separately and simultaneously. Multiple regression analyses were used to evaluate how age and hearing thresholds affect speech recognition and listening effort scores.

RESULTS

Results of the multiple regression analyses showed that age is a significant determinant of listening effort, whereby listening effort increases with increasing age even when age-related variance in speech recognition is partialled out. On the basis of the regression equations and the median score for listening effort, it was found that listening effort started to increase in the fourth decade of life.

CONCLUSIONS

This study was a first exploration of listening effort from young to older adults and showed that, independent of hearing sensitivity, listening effort increases with age. To be more specific, there is a need to further investigate the cognitive functions important for speech communication while exploring their possible relationship with listening effort.

Red light violations by adult pedestrians and other safety-related behaviors at signalized crosswalks

To study human factors linked to red light violations, and more generally to safety-related behaviors at signalized crosswalks, the present study combines the collection of observational data with questionnaires answered by 422 French adult pedestrians. Thirteen behavioral indicators were extracted (12 before and while crossing, and red light violation), and the roles of several demographical, contextual and mobility-associated variables were examined. The results of the stepwise logistic regression analyses carried out on each of the 12 behavioral indicators observed before and while crossing revealed that gender had no major impact, but age did, with more cautious behaviors as pedestrians were older. The three contextual variables (group size, parked vehicles, and traffic density), as four mobility-associated variables (driving and walking experiences, self-reported crossing difficulties and falls in the street) were also found to be important factors in safety-related crossing behaviors. A wider logistic regression analysis, made specifically on red light violations with all behavioral indicators observed before and while crossings and the several demographical, contextual and mobility-associated variables put together, showed that red light violations were mostly affected by current situational factors (group size, parked vehicles) and particularly associated with some behavioral patterns (looking toward the traffic, the ground, the light, running and crossing diagonally). The overall results encourage the development of safer pedestrian infrastructures and engineering countermeasures.

Efficacy of auditory training in elderly subjects

Auditory training (AT) has been used for auditory rehabilitation in elderly individuals and is an effective tool for optimizing speech processing in this population. However, it is necessary to distinguish training-related improvements from placebo and test-retest effects. Thus, we investigated the efficacy of short-term AT [acoustically controlled auditory training (ACAT)] in elderly subjects through behavioral measures and P300. Sixteen elderly individuals with auditory processing disorder (APD) received an initial evaluation (evaluation 1 - E1) consisting of behavioral and electrophysiological tests (P300 evoked by tone burst and speech sounds) to evaluate their auditory processing. The individuals were divided into two groups. The Active Control Group (n = 8) underwent placebo training. The Passive Control Group (n = 8) did not receive any intervention. After 12 weeks, the subjects were revaluated (evaluation 2 - E2). Then, all of the subjects underwent ACAT. Following another 12 weeks (eight training sessions), they underwent the final evaluation (evaluation 3 - E3). There was no significant difference between E1 and E2 in the behavioral test [F(9.6) = 0.06, p = 0.92, λ de Wilks = 0.65)] or P300 [F(8.7) = 2.11, p = 0.17, λ de Wilks = 0.29] (discarding the presence of placebo effects and test-retest). A significant improvement was observed between the pre- and post-ACAT conditions (E2 and E3) for all auditory skills according to the behavioral methods [F(4.27) = 0.18, p = 0.94, λ de Wilks = 0.97]. However, the same result was not observed for P300 in any condition. There was no significant difference between P300 stimuli. The ACAT improved the behavioral performance of the elderly for all auditory skills and was an effective method for hearing rehabilitation.

Age-related changes of auditory brainstem responses in nonhuman primates

Nonhuman primates, compared with humans and rodents, have historically been far less used for studies of age-related hearing loss, primarily because of their long life span and high cost of maintenance. Strong similarities in genetics, anatomy, and neurophysiology of the auditory nervous system between humans and monkeys, however, could provide fruitful opportunities to enhance our understanding of hearing loss. The present study used a common, noninvasive technique for testing hearing sensitivity in humans, the auditory brainstem response (ABR), to assess the hearing of 48 rhesus macaques from 6 to 35 yr of age to clicks and tone stimuli between 0.5 and 16.0 kHz. Old monkeys, particularly those above 21.5 yr of age, had missing ABR waveforms at high frequencies. Regression analyses revealed that ABR threshold increased as a function of age at peaks II and IV simultaneously. In the suprathreshold hearing condition (70 dB peak sound pressure level), ABR-based audiograms similarly varied as a function of age such that old monkeys had smaller peak amplitudes and delayed latencies at low, middle, and high frequencies. Peripheral hearing differences remained a major influence associated with age-related changes in audiometric functions of old monkeys at a comparable sensation level across animals. The present findings suggest that hearing loss occurs in old monkeys across a wide range of frequencies and that these deficits increase in severity with age. Parallel to prior studies in monkeys, we found weak effects of sex on hearing, and future investigations are necessary to clarify its role in age-related hearing loss.

Aging and Speech Understanding

As people age, structural as well as neural degeneration occurs throughout the auditory system. Many older adults experience difficulty in understanding speech especially in adverse listening conditions although they can hear speech sounds. According to a report of the Committee on Hearing and Bioacoustics and Biomechanics of the National Research Council, peripheral, central-auditory, and cognitive systems have long been considered major factors affecting the understanding of speech. The present study aims to review 1) age-related changes in the peripheral, central-auditory, and cognitive systems, 2) the resulting decline in the understanding of speech, and 3) the clinical implication for audiologic rehabilitation of older adults. Once the factors affecting the understanding of speech in older adults are identified and the characteristics of age-related speech understanding difficulties are examined, clinical management could be developed for prevention and treatment. Future research about problems related to the understanding of speech in older adults will help to improve the quality of life in the elderly.

Brainstem encoding of speech and musical stimuli in congenital amusia: evidence from Cantonese speakers

Congenital amusia is a neurodevelopmental disorder of musical processing that also impacts subtle aspects of speech processing. It remains debated at what stage(s) of auditory processing deficits in amusia arise. In this study, we investigated whether amusia originates from impaired subcortical encoding of speech (in quiet and noise) and musical sounds in the brainstem. Fourteen Cantonese-speaking amusics and 14 matched controls passively listened to six Cantonese lexical tones in quiet, two Cantonese tones in noise (signal-to-noise ratios at 0 and 20 dB), and two cello tones in quiet while their frequency-following responses (FFRs) to these tones were recorded. All participants also completed a behavioral lexical tone identification task. The results indicated normal brainstem encoding of pitch in speech (in quiet and noise) and musical stimuli in amusics relative to controls, as measured by FFR pitch strength, pitch error, and stimulus-to-response correlation. There was also no group difference in neural conduction time or FFR amplitudes. Both groups demonstrated better FFRs to speech (in quiet and noise) than to musical stimuli. However, a significant group difference was observed for tone identification, with amusics showing significantly lower accuracy than controls. Analysis of the tone confusion matrices suggested that amusics were more likely than controls to confuse between tones that shared similar acoustic features. Interestingly, this deficit in lexical tone identification was not coupled with brainstem abnormality for either speech or musical stimuli. Together, our results suggest that the amusic brainstem is not functioning abnormally, although higher-order linguistic pitch processing is impaired in amusia. This finding has significant implications for theories of central auditory processing, requiring further investigations into how different stages of auditory processing interact in the human brain.

Correlation between the characteristics of resonance and aging of the external ear

PURPOSE

Aging causes changes in the external ear as a collapse of the external auditory canal and tympanic membrane senile. Knowing them is appropriate for the diagnosis of hearing loss and selection of hearing aids. For this reason, the study aimed to verify the influence of the anatomical changes of the external ear resonance in the auditory canal in the elderly.

METHODS

The sample consisted of objective measures of the external ear of elderly with collapse (group A), senile tympanic membrane (group B) and without changing the external auditory canal or tympanic membrane (group C) and adults without changing the external ear (group D). In the retrospective/clinical study were performed comparisons of measures of individuals with and without alteration of the external ear through the gain and response external ear resonant frequency and the primary peak to the right ear.

RESULTS

In groups A, B and C was no statistically significant difference between Real Ear Unaided Response (REUR) and Real Ear Unaided Gain (REUG), but not for the peak frequency. For groups A and B were shown significant differences in REUR and REUG. Between the C and D groups were significant statistics to the REUR and REUG, but not for the frequency of the primary peak.

CONCLUSION

Changes influence the external ear resonance, decreasing its amplitude. However, the frequency of the primary peak is not affected.

Hearing and age-related changes in the gray mouse lemur

In order to examine auditory thresholds and hearing sensitivity during aging in the gray mouse lemur (Microcebus murinus), suggested to represent a model for early primate evolution and Alzheimer research, we applied brainstem-evoked response audiometry (BERA), traditionally used for screening hearing sensitivity in human babies. To assess the effect of age, we determined auditory thresholds in two age groups of adult mouse lemurs (young adults, 1-5 years; old adults, ≥7 years) using clicks and tone pips. Auditory thresholds indicated frequency sensitivity from 800 Hz to almost 50 kHz, covering the species tonal communication range with fundamentals from about 8 to 40 kHz. The frequency of best hearing at 7.9 kHz was slightly lower than that and coincided with the dominant frequencies of communication signals of a predator. Aging shifted auditory thresholds in the range between 2 and 50.4 kHz significantly by 12-27 dB. This mild presbyacusis, expressed in a drop of amplitudes of BERA signals, but not discernible in latencies of responses, suggests a metabolic age-related decrease potentially combined with an accompanying degeneration of the cochlear nerve. Our findings on hearing range of this species support the hypothesis that predation was a driving factor for the evolution of hearing in small ancestral primates. Likewise, results provide the empirical basis for future approaches trying to differentiate peripheral from central factors when studying Alzheimer's disease-like pathologies in the aging brain.

Temporal characteristics of speech: the effect of age and speech style

Aging affects temporal characteristics of speech. It is still a question how these changes occur in different speech styles which require various cognitive skills. In this paper speech rate, articulation rate, and pauses of 20 young and 20 old speakers are analyzed in four speech styles: spontaneous narrative, narrative recalls, a three-participant conversation, and reading aloud. Results show that age has a significant effect only on speech rate, articulation rate, and frequency of pauses. Speech style has a higher effect on temporal parameters than speakers' age.

Voice onset time and speakers' age: data from Hungarian

The aim of this paper was to investigate the VOT of voiceless plosives (/p, t, k/) in the speech of Hungarian-speaking elderly. Read speech of 25 old (70 to 90 years) and 25 young (21 to 32 years) was analyzed. In each recording, the VOT of phonologically short [p, t, k] was measured. Our data show that VOT values of all three types of voiceless plosives would exhibit significant differences both in old and in young Hungarians' speech. Bilabial and alveolar plosives had significantly longer VOT in old subjects' speech than in that of young subjects, while old subjects produced significantly shorter VOTs in pronouncing [k] than their younger peers. We argue that these results are attributable to (1) significantly slower rate of articulation (yielding longer speech sounds in general), and (2) the articulatory and aerodynamic background of the production of plosives.

Managing age-related hearing loss: how to use hearing aids efficiently - a mini-review

Using hearing aids may contribute to better functioning in the everyday lives of hearing-impaired older individuals. We introduce an integrative concept for the efficient use of hearing aids that involves both satisfaction with, and behaviour towards, hearing aids. We review theoretical and empirical work on the predictors of the efficient use of hearing aids in everyday life. Furthermore, we contend that the use of hearing aids requires improved understanding of the variability of hearing demands within specific contexts of everyday life (e.g. conversation with family members, listening to music). The efficiency of hearing aid use thus depends on the fit of situational demands, personal resources, and the specific configuration of the hearing aid device. We propose an integrative person-environment-fit model that advances concepts of selection, optimisation, and compensation to hearing aid efficiency. We discuss the implications of this model for research and for practitioners in the field of gerontology.

Age-related deterioration of the representation of space in human auditory cortex

One of the principal auditory disabilities associated with older age is difficulty in locating and tracking sources of sound. This study investigated whether these difficulties are associated with deterioration in the representation of space in the auditory cortex. In psychophysical tests, half of a group of older (>60 years) adults displayed spatial acuity similar to that of young adults throughout the frontal horizontal plane. The remaining half had considerably poorer spatial acuity at the more peripheral regions of frontal space. Computational modeling of electroencephalographic responses to abrupt location shifts demonstrated marked differences in the spatial tuning of populations of cortical neurons between the older adults with poor spatial acuity on the one hand, and those with good spatial acuity, as well as young adults, on the other hand. In those with poor spatial acuity, cortical responses contained little information with which to distinguish peripheral locations. We demonstrate a clear link between neural responses and spatial acuity measured behaviorally, and provide evidence for age-related changes in the coding of horizontal space.

The Effects of Aging on Auditory Processing and Cognition

Purpose

To briefly summarize existing data on effects of aging on auditory processing and cognition.

Method

A narrative review summarized previously reported data on age-related changes in auditory processing and in cognitive processes with a focus on spoken language comprehension and memory. In addition, recent data on effects of lifestyle engagement on cognitive processes are reviewed.

Results

There is substantial evidence for age-related declines in both auditory processes and cognitive abilities. Accumulating evidence supports the idea that the perceptual burden associated with hearing loss impacts the processing resources available for good comprehension and memory for spoken language, particularly in older adults with limited resources. However, many language abilities are well preserved in old age, and there is considerable variability among individuals in cognitive performance across the life span. The authors discuss how lifestyle factors and socioemotional engagement can help to offset declining abilities.

Conclusions

It is clear that spoken language processing in adulthood and old age is affected by changes in perceptual, cognitive, and socioemotional processes as well as by interactions among these changes. Recommendations for further research include studying speech comprehension in complex conditions, including meaningful-connection spoken language, and tailoring clinical interventions based on patients' auditory processing and cognitive abilities along with their individual socioemotional demands.

Effect of rate-alteration on speech perception in noise in older adults with normal hearing and hearing impairment

PURPOSE

The purpose of this study was to evaluate the effect of using slow and fast speaking rates in competing noise on older adults with normal hearing (NH) and those with hearing impairment (HI).

METHOD

Thirty-four older adults (56-85 years) were grouped based on hearing ability-NH (N = 15) and HI (N = 19). Rate-altered Quick Speech-in-Noise Test (QuickSIN; Etymotic Research, 2001) stimuli were presented at 3 speech rates (slow, average, and fast), and the signal-to-noise ratio (SNR) loss was calculated for each.

RESULTS

The older participants with HI had significantly higher SNR loss than the NH participants at all 3 speech rates. The NH participants showed improved speech perception in noise when a slow rate of speech was used. This benefit was not observed for the participants with HI. Both groups performed poorly with the fastest speech rate.

CONCLUSION

Results suggest that older adults with HI who are not wearing hearing aids are not able to take advantage of additional processing time afforded by the use of slow speaking rates when speech (70-75 dB HL) is presented in competing noise. Additionally, the use of a fast speaking rate significantly reduces an individual's ability to perceive speech in noise, regardless of hearing status. Decreasing from a fast speaking rate to an average rate is beneficial and should be recommended by audiologists to increase the likelihood of older adults understanding speech in noise.

Correlation between plasma levels of radical scavengers and hearing threshold among elderly subjects with age-related hearing loss

CONCLUSION

Low plasma melatonin is significant in the development of high frequency hearing loss (HL) among the elderly.

OBJECTIVE

To determine the correlation between hearing threshold and the plasma melatonin and ascorbic acid (vitamin C).

METHODS

This was a cross-sectional study involving 126 apparently healthy elderly subjects, 59 males and 67 females, aged >60 years. Subjects underwent pure tone audiometry and plasma melatonin and vitamin C were assayed using high-performance liquid chromatography.

RESULTS

The mean ± SD of plasma melatonin among the subjects with normal hearing (NH) (0-30 dB) and those with HL in the speech frequencies was 18.3 ± 3.6 μg/L and 16.4 ± 4.7 μg/L, respectively. In the high frequencies the values were 17.7 ± 6.2 μg/L and 13.1 ± 6.4 μg/L for NH and HL, respectively. For vitamin C, the mean ± SD among subjects with NH and those with HL in the speech frequencies were 1.2 ± 0.2 μg/L and 1.0 ± 0.1 μg/L, respectively. In the high frequencies, the values were 1.0 ± 0.2 μg/L and 0.9 ± 0.3 μg/L for NH and HL, respectively. Among subjects with high frequency HL, Spearman's correlation revealed significant correlation between increasing hearing threshold and melatonin (correlation coefficient = -0.30, p = 0.01), but not for vitamin C (correlation coefficient = -0.12, p = 0.22). Linear regression, adjusting for age, still revealed significant correlation between the melatonin (correlation coefficient = -0.03, p = 0.00) and hearing threshold in the high frequencies.

Percepção de fala em idosos: análise dos erros

OBJETIVO: analisar os erros apresentados em um teste de fala na presença de ruído competitivo de idosos. MÉTODO: foi realizado estudo retrospectivo com levantamento de dados de prontuário de 55 idosos divididos em grupo controle (GC) e grupo estudo (GE), considerando os testes Índice Percentual de Reconhecimento de Fala (IPRF) e Fala com Ruído (F/R). RESULTADO: as trocas articulatórias foram mais frequentes no GE e no teste F/R. De maneira geral, ocorreram mais omissões de fonemas na posição inicial (/p/ e /b/) e final (/s/) dos vocábulos, principalmente com o ruído. Houve omissões de vocábulos somente no GE. Os vocábulos mais trocados no GC foram "rir ", "dil ", "lhe ", "faz " e "rol ", e no GE, "rir ", "dil ", "lhe ", "faz ", "pus " e "rol ". CONCLUSÃO: a presença de limiares tonais normais não impediu que ocorressem erros no reconhecimento de fala e o ruído interferiu negativamente neste reconhecimento, principalmente no idoso com perda auditiva. Os fonemas /p/, /b/ e /s/ foram os mais frequentemente omitidos, principalmente na presença do ruído competitivo. Os vocábulos "rir ", "dil ", "lhe ", "faz " e "rol " foram os mais trocados para os grupos avaliados, sobretudo na presença do ruído.

Formal auditory training in elderly hearing aid users

It is of paramount importance to install hearing rehabilitation programs for the elderly. Aim: to check the efficacy of a forma auditory training program for elderly patients fitted with hearing aids for at least three months, by means of speech recognition tests and self-assessment questionnaires. Methods: longitudinal contemporary cohort study. We selected 13 elderly hearing aid users, using intra-canal hearing aids in both ears, from both genders, with average age of 65.3 years. This group was randomly divided in Experiment Group and Control Group. The Experiment Group underwent seven formal auditory training sessions, aiming at stimulating their hearing skills for hearing closing, memory, attention, background figure and binaural integration. The participants were assessed by three behavioral tests and one self assessment questionnaire. Results: The elderly from the Experiment Group had significantly better performance in the assessments after auditory training in comparison to the Control Group. Conclusion: the formal auditory training program in a soundproof booth, associated with the use of hearing aids, improves speech recognition performance and reduces the perception of auditory handicap for the elderly who use intra-canal hearing aids.

Effects of aging on inner ear morphology in dogs in relation to brainstem responses to toneburst auditory stimuli

BACKGROUND

Age-related hearing loss (ARHL) is the most common form of hearing loss in humans and is increasingly recognized in dogs.

HYPOTHESIS

Cochlear lesions in dogs with ARHL are similar to those in humans and the severity of the histological changes is reflected in tone audiograms.

ANIMALS

Ten geriatric dogs (mean age: 12.7 years) and three 9-month-old dogs serving as controls for histological analysis.

METHODS

Observational study. Auditory thresholds were determined by recording brainstem responses (BERA) to toneburst auditory stimuli (1, 2, 4, 8, 12, 16, 24, and 32 kHz). After euthanasia and perfusion fixation, the temporal bones were harvested and processed for histological examination of the cochleas. The numbers of outer hair cells (OHCs) and inner hair cells (IHCs) were counted and the spiral ganglion cell (SGC) packing density and stria vascularis cross-sectional area (SVCA) were determined.

RESULTS

A combination of cochlear lesions was found in all geriatric dogs. There were significant reductions (P .001) in OHC (42%, 95% confidence interval [CI]; 24-64%) and IHC counts (21%, 95% CI; 62-90%) and SGC packing densities (323, 95% CI; 216-290) in the basal turn, SVCA was smaller in all turns. The greatest reduction in auditory sensitivity was at 8-32 kHz.

CONCLUSIONS AND CLINICAL IMPORTANCE

ARHL in this specific population of geriatric dogs was comparable histologically to the mixed type of ARHL in humans. The predominance of histological changes in the basal cochlear turn was consistent with the large threshold shifts observed in the middle- to high-frequency region.

Role of oxidative stress in hearing impairment in patients with type two diabetes mellitus

OBJECTIVE

Although many clinical investigations have found a relationship between hearing loss and diabetes mellitus, the pathophysiology of this effect remains controversial. To date, the mechanisms of hearing loss in diabetic patients have been explained in terms of microangiopathy, neuropathy and encephalopathy. However, many reports indicate that some diabetic complications are associated with oxidative stress related to the diabetes itself. In the present study, we hypothesised that oxidative stress may be a cause of hearing loss in diabetic patients.

METHODS

The study group comprised non-insulin dependent diabetic patients with no signs of microangiopathy or peripheral neuropathy. The control group comprised sex-, age- and body weight matched, non-diabetic subjects. Auditory function was evaluated using pure tone audiometry and tympanometry. Subjects with normal hearing and sensorineural hearing loss were included in the study, whereas subjects with conductive hearing loss were excluded. Both the study group (n = 63) and the control group (n = 37) were divided into subgroups based on the presence and absence of hearing loss. Oxidative stress was evaluated by measuring serum indicators of protein oxidation and lipid peroxidation, serum levels of nitric oxide and various non-enzymatic antioxidants, and the activity of various enzymatic antioxidants.

RESULTS

The non-insulin dependent diabetic patients had significantly higher serum levels of protein oxidation products, nitric oxide, enzymatic antioxidant activity (i.e. glutathione peroxidase and superoxide dismutase), compared with the control group (p < 0.05). When we compared the groups in relation to the presence of hearing loss, the nitric oxide level was significantly increased in the diabetic group with good hearing, compared with diabetic patients with hearing loss (p = 0.014). In the diabetic group, a clear, negative correlation was observed between serum levels of nitric oxide and vitamins C and E, and hearing impairment (r = -0.395, r = -0.318, r = -0.500, respectively). There was also a positive correlation between serum vitamin C concentrations and hearing levels in the control group (r = 0.417).

CONCLUSION

These results suggest that oxidative stress may play an important role in hearing impairment in diabetic patients. In this process, increased protein oxidation appears to be more important than lipid peroxidation. Nitric oxide may have a protective effect on hearing, as may some nonenzymatic antioxidants such as vitamin C and E.

Radical scavengers for elderly patients with age-related hearing loss

CONCLUSION

The results of this study suggest that treatment with radical scavengers has the potential to become an effective new therapy for age-related hearing loss.

OBJECTIVE

To assess the efficacy of treatment with radical scavengers for age-related hearing loss.

SUBJECTS AND METHODS

Rebamipide (300 mg/day), alpha-lipoic acid (60 mg/day), and vitamin C (600 mg/day) were given orally for at least 8 weeks to 46 elderly patients with age-related hearing loss.

RESULTS

Hearing levels after treatment were significantly improved at all frequencies.

Group follow up proposal for elderly with hearing aids

Summary

Implementing rehabilitation programs to hearing impaired adults is of great importance, mainly in the elderly population, and it is necessary to add them to the routine of outpatient care programs.

Aim

to present a group care program for elderly patients who are fitted with hearing aids.

Material and method

to carry out a pilot study of clinical and experimental type, with the participation of 40 elderly users of hearing aids donated by the government, distributed within six groups, with maximum of eight participants jointly with their respective companions. Program consisted of three meetings every fifteen days, where information and education on the proper use hearing aids was transmitted.

Results

Most of the patients participated actively in the meetings spontaneously giving their opinion or answering questions when so requested. All elderly had been informed as to the importance of accepting their auditory deficiency and on the need to be motivated towards using hearing aids. Moreover, listening to depositions of other elderly users seemed to facilitate understanding of their own difficulties and stimulated them in the process of getting used to the sound amplification.

Conclusion

Groups structure facilitated interaction among aged ones, helping them to clarify communication doubts and strategies and, consequently, it promoted their adaptation.

Technologic advances in aural rehabilitation: applications and innovative methods of service delivery

The level of interest in aural rehabilitation has increased recently, both in clinical use and in research presentations and publications. Advances in aural rehabilitation have seen previous techniques such as speech tracking and analytic auditory training reappear in computerized forms. These new delivery methods allow for a consistent, cost-effective, and convenient training program. Several computerized aural rehabilitation programs for hearing aid wearers and cochlear implant recipients have recently been developed and were reported on at the 2006 State of the Science Conference of the Rehabilitation Engineering Research Center on Hearing Enhancement at Gallaudet University. This article reviews these programs and outlines the similarities and differences in their design. Another promising area of aural rehabilitation research is the use of pharmaceuticals in the rehabilitation process. The results from a study of the effect of d-amphetamine in conjunction with intensive aural rehabilitation with cochlear implant patients are also described.