Effect of Cognitive Rehabilitation by Auditory Stroop Training on Quality of Life of Individuals with Tinnitus

Background: Studies have shown that tinnitus patients have difficulties in cognitive function such as memory and attention. The Stroop task engages the attention network where one aspect of the stimulus is noticed while the other one is ignored. Thus, Stroop training can improve the patient's cognitive control and ability to ignore the tinnitus signal. Method: Thirty chronic tinnitus (> 6 months) patients were included in this study. They were distributed into two 15-member groups: intervention and control. Common audiometric, psychometric, and psychoacoustic evaluations of tinnitus were performed for two groups before intervention and after auditory Stroop training of group 1. Results: There was significant difference in the quality of life and THI scores, VAS of annoyance, and reaction time of Stroop task before and after intervention in group1. The decreased reaction time was positively correlated with improved quality of life, THI score, and VAS of annoyance. Conclusion: Cognitive rehabilitation using tasks such as auditory Stroop can be effective in controlling tinnitus by improving cognitive control.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-023-04011-w.

Combined Bifrontal Transcranial Direct Current Stimulation and Auditory Stroop Training in Chronic Tinnitus

Patients with tinnitus experience difficulties in cognitive control and executive functions. Many of which are regarded as the cause of tinnitus rather than its complications. Methods for the improvement of inhibitory and cognitive control seem to be effective in the control of tinnitus. In this study, transcranial direct current stimulation and auditory Stroop exercise were have been to improve inhibitory control and the ability to ignore tinnitus in patients suffering from chronic tinnitus. 34 patients with chronic tinnitus (> 6 months) were randomly divided into two groups. The first group consist of 17 patients who received 6 sessions of tDCS followed by 6 sessions of auditory Stroop training. The second group received 6 sessions of sham tDCS followed by 6 sessions of auditory Stroop training. The initial evaluations including pure tone audiometry, psychoacoustic measurements, tinnitus handicap inventory (THI) survey and visual analog scale (VAS) of annoyance and loudness were performed before, immediately after, and one month after the tDCS, sham, and Stroop training. The results of this study revealed a significant reduction in THI score, VAS of loudness, and annoyance of tinnitus. A significant correlation was detected between the reaction time of incongruent words in the Stroop task and improvement of THI score and VAS of annoyance. Combined tDCS and Stroop training efficiently improve chronic tinnitus.

Testing A Hypothesis: Tinnitus Control by Enhancing Physiological Inhibition

Background

Deficit in cognitive functions and central executive function is one of the popular hypotheses on the underlying cause of tinnitus. Some studies expressed the effect of tinnitus on the inhibitory cognitive tasks, referring to the slower inhibitory results such as in the Stroop task in the people suffering from tinnitus as compared to normal subjects. Since Stroop engages the network overlapping the attention and tinnitus distress networks, it seems likely that Stroop exercises can effectively contribute to controlling the tinnitus and its consequent distress through improvement of the cognitive function and increasing the physiological inhibition.

Method

A total of 25 patients with chronic tinnitus (> 6 months) were randomly divided into two groups: an intervention group of 15 patients and a control group of 10 patients. Both groups were subjected to initial evaluations including pure tone audiometry, psychoacoustic measurements, tinnitus handicap inventory (THI) survey, and visual analogue scale (VAS) of annoyance and loudness. The intervention group underwent a rehabilitation program consisting of 6 Stroop training sessions. The control group didn't receive any training. Afterwards, both groups were reevaluated and the results were compared to those of initial evaluations.

Results

Results of this study indicated significant differences in THI scores and VAS of annoyance, before and after Stroop training in the intervention group, although no significant difference was observed when it came to VAS of loudness.

Conclusion

Successive sessions of conflict processing training can improve the annoyance of tinnitus by enhancing the patient's inhibition control, making this task a safe practice for tinnitus treatment.

Impact of Combined Bifrontal Transcranial Direct- Current Stimulation and Conflict Processing Training on Tinnitus: a Protocol for Single-Blind Randomized Controlled Trial

Background and Aim: The deficit in cognitive functions and central executive function is one of the popular hypotheses on the underlying cause of tinnitus. These factors are not only the complications of tinnitus but are also involved in the generation of it. In this study, bifrontal transcranial Direct Current Stimulation (tDCS) and conflict processing will be used in the form of auditory Stroop training to improve cognitive performance and inhibition control for tinnitus management. Methods: This study will be carried out on 34 chronic tinnitus patients. The initial evaluations include the tinnitus psychoacoustic evaluations, determination of the tinnitus handicap through tinnitus handicap inventory, and examining the annoyance and loudness of tinnitus through the visual analog scale after which the participants will be investigated in two groups. The first group will receive sessions of tDCS followed by six sessions of conflict processing training. The second group will first receive tDCS in the form of sham, to be followed by six sessions of auditory Stroop. The evaluations will be repeated after each intervention. Discussion: Studies have shown that successive sessions of conflict processing training can enhance cognitive plasticity and inhibition function. As conflict processing training has not been addressed as rehabilitation training in the people suffering from tinnitus, these processes will be designed in four tasks as rehabilitation exercises in Farsi language and applied along with tDCS to the people with chronic tinnitus to decrease and control tinnitus by improving cognitive and inhibition control. Trial registration: Iranian Registry of Clinical Trials (IRCT20120215009014N366) on Sep 17th, 2020. Keywords: Tinnitus; conflict processing; Stroop training; inhibition

Can Galvanic Vestibular Stimulation Be an Effective Management for Bilateral Vestibulopathy?

Background: Vestibulo-ocular and vestibulospinal reflexes contribute to postural stability and gaze stabilization during head and body movements. Thus, chronic disequilibrium, postural imbalance, and oscillopsia occur after bilateral vestibulopathy (BVP). This disorder reduces the daily physical activity and seriously affects the quality of life. Because of its limiting and hazardous consequences, it is necessary to plan an effective therapeutic and rehabilitative strategy for BVP. Recent attempts have used the beneficial effects of stochastic resonance through noisy galvanic vestibular stimulation (nGVS) for this purpose. The present paper aimed to review the effects of nGVS on balance functions in patients with BVP.

Methods: This review article investigated research papers in the field of usefulness of nGVS in the treatment of BVP. In the initial search, a total of 134 articles were found with keywords of this manuscript in the SID, Google Scholar, Science Direct, and PubMed databases, of which 7 articles were considered relevant to our subject.

Results: The results of these articles suggest that nGVS can have ameliorating effects on the static and dynamic balance as well as on the vestibular performance in BVP patients.

Conclusion: In BVP, nGVS may be useful in designing prosthetics for permanent use by the patient, and/or as a method for enhancing the neuroplasticity in combination with other therapies, such as vestibular rehabilitation.

Long Latency Auditory Evoked Potentials and Object-Related Negativity Based on Harmonicity in Hearing-Impaired Children

Hearing-impaired children (HIC) have difficulty understanding speech in noise, which may be due to difficulty parsing concurrent sound object based on harmonicity cues. Using long latency auditory evoked potentials (LLAEPs) and object-related negativity (ORN), a neural metric of concurrent sound segregation, this study investigated the sensitivity of HIC in processing harmonic relation. The participants were 14 normal-hearing children (NHC) with an average age of 7.82 ± 1.31 years and 17 HIC with an average age of 7.98 ± 1.25 years. They were presented with a sequence of 200 Hz harmonic complex tones that had either all harmonic in tune or the third harmonic mistuned by 2%, 4%, 8%, and 16% of its original value while neuroelectric brain activity was recorded. The analysis of scalp-recorded LLAEPs revealed lower N2 amplitudes elicited by the tuned stimuli in HIC than control. The ORN, isolated in difference wave between LLAEP elicited by tuned and mistuned stimuli, was delayed and smaller in HIC than NHC. This study showed that deficits in processing harmonic relation in HIC, which may contribute to their difficulty in understanding speech in noise. As a result, top-down and bottom-up rehabilitations aiming to improve processing of basic acoustic characteristics, including harmonics are recommended for children with hearing loss.

Comparison of efficacy of vestibular rehabilitation and noisy galvanic vestibular stimulation to improve dizziness and balance in patients with multiple sclerosis

BACKGROUND

Dizziness and imbalance are common symptoms in patients with multiple sclerosis (PwMS), and rehabilitation interventions varying greatly in effectiveness.

OBJECTIVE

To compare the effectiveness of vestibular rehabilitation therapy (VRT) and noisy galvanic vestibular stimulation (nGVS) on dizziness and balance in PwMS.

METHODS

This was a single-blind, randomized controlled trial. Twenty-four PwMS were randomly divided into groups of VRT, nGVS, and Control. The VRT and the nGVS groups underwent the intervention program. The patients were assessed with the composite score in anteroposterior and lateral directions (CS AP and LAT) obtained by sensory organization test (SOT), Dizziness Handicap Inventory (DHI), and Activities-Specific Balance Confidence Scale (ABC).

RESULTS

The VRT group showed greater improvements in CS AP and LAT, DHI total score, and ABC total score compared with the nGVS group and the control group. No significant difference was found between the nGVS group and the control group. These results were approximately stable at the 4-week follow-up.

CONCLUSIONS

These findings provided evidence for effectiveness of the VRT in improvement of dizziness and balance in PwMS. These improvements were not associated with the nGVS. Further studies are needed to assess the effectiveness of the nGVS on dizziness and balance in PwMS.

Transcranial direct current stimulation in treatment of tinnitus

Background and Aim: Approximately 20% of general population is struggling with tinnitus. Recent theories on tinnitus are mainly based on impairments in the central auditory system that can lead to tinnitus. Recent studies have shown that tinnitus is not simply a result of the involvement of one brain region or pathway; but it can be caused by simultaneous involvement of multiple brain regions. Due to lack of information about the tinnitus etiology, site, and pathophysiology, there is still no any specific and common method for its management. In recent years, neuromodulation techniques such as transcranial direct current stimulation (tDCS) has been proposed for management of tinnitus. In this study, we aimed to review the role of tDCS in tinnitus management. Recent Findings: Based on the inclusion criteria, 7 eligible articles were selected for review. Most of them showed the beneficial effects of tDCS on tinnitus management. Conclusion: The tDCS can be an effective technique for management of tinnitus. One of the main challenges for using tDCS in tinnitus patients is the differnce in stimulation parameters; therefore, more studies are recommended for obtaining its ideal parameters. Recent Findings: Based on the inclusion criteria, 7 eligible articles were selected for review. Most of them showed the beneficial effects of tDCS on tinnitus management. Conclusion: The tDCS can be an effective technique for management of tinnitus. One of the main challenges for using tDCS in tinnitus patients is the differnce in stimulation parameters; therefore, more studies are recommended for obtaining its ideal parameters. Keywords: Transcranial direct current stimulation; tinnitus; neuromodulation

An introductory overview of bimodal fitting

Background and Aim: In a bimodal fitting, one ear is stimulated acoustically with a hearing aid and the other is stimulated electrically with a cochlear implant. This paper provides a brief summary of the concept of bimodal fitting, binaural hearing and its importance, the hearing benefits of binaural hearing in bimodal fitting, candidacy and hearing aid adjustment in bimodal fitting cases. Recent Findings: Researches have shown that bimodal fitting offers a wide range of hearing benefits over unilateral cochlear implants, such as better speech perception in noise, better musical perception, and a better understanding of pitch and tone perception and naturalness of sound perception. Conclusion: Considering the binaural hearing advantages in bimodal fitting users, it can be concluded that users of unilateral cochlear implants who have measurable residual hearing in their non-implanted ear can use a hearing aid in that ear and enjoy binaural hearing advantages. The hearing aid should be fitted in a way to complement the information obtained through cochlear implantation. Keywords: Bimodal fitting; cochlear implant; binaural hearing

Few tips for management of tinnitus

The article's abstract is not available.  

Effect of Vowel Auditory Training on the Speech-In-Noise Perception among Older Adults with Normal Hearing

Introduction:

Aging reduces the ability to understand speech in noise. Hearing rehabilitation is one of the ways to help older people communicate effectively. This study aimed to investigate the effect of vowel auditory training on the improvement of speech-in-noise (SIN) perception among elderly listeners.

Materials and Methods:

This study was conducted on 36 elderly listeners (17 males and 15 females) with the mean±SD of 67.6±6.33. They had the normal peripheral auditory ability but had difficulties in SIN perception. The samples were randomly divided into two groups of intervention and control. The intervention group underwent vowel auditory training; however, the control group received no training.

Results:

After vowel auditory training, the intervention group showed significant changes in the results of the SIN test at two signal-to-noise ratios of 0 and -10 and the Iranian version of the Speech, Spatial, and Qualities of Hearing Scale, compared to the control group (P<0.001). Regarding the Speech Auditory Brainstem Response test, the F₀ magnitude was higher in the intervention group (8.42±2.26), compared to the control group (6.68±1.87) (P<0.011).

Conclusion:

This study investigated the effect of vowel auditory training on the improvement of SIN perception which could be probably due to better F₀ encoding and receiving. This ability enhancement resulted in the easier perception of speech and its more proper separation from background noise which in turn enhanced the ability of the old people to follow the speech of a specific person and track the discussion.

Auditory temporal processing assessment in children with developmental stuttering

OBJECTIVE

Stuttering is a developmental disorder of speech production with a dynamic and multifactorial nature. Scientific theories mentioned the role of auditory processing disorder in stuttering. Investigating the auditory processing in stuttering would provide insights into the mechanisms of stuttering. The details of basic auditory processing in children with stuttering (CWS) continue to remain uncertain. This study aimed to investigate the auditory temporal processing (ATP) in CWS and also its relationship with the stuttering severity.

METHODS

The participants of this comparative cross-sectional study were 54 CWS and 63 children without stuttering (CWOS). All children were between 7 and 12 years old. ATP ability of the participants was measured using the Backward Masking (BM), Duration Pattern (DP), and Gap in Noise (GIN) tests. Then, the groups were compared in terms of ATP results. The correlation between the scores of these tests and stuttering severity was assessed.

RESULTS

According to the results, CWS showed poorer performance on DP, BM and GIN tests when compared with CWOS. Moreover, the stuttering severity had a significant negative correlation with the DP scores and percentage of correct identification scores in GIN; whereas it had a significant positive correlation with the BM thresholds.

CONCLUSIONS

The results showed that some CWS have ATP disorder, which could exacerbate their stuttering. These findings highlighted the role of ATP disorder in stuttering.

Spectro-temporal modulation detection and its relation to speech perception in children with auditory processing disorder

OBJECTIVES

Poor speech perception in noise is one of the most common complaints reported for children with auditory processing disorder (APD). APD is defined as a deficit in perceptual processing of acoustic information in the auditory system in which decreased spectro-temporal resolution may also contribute. Since the recognition of spoken message in the context of other sounds, is based on the processing of auditory spectro-temporal modulations, the assessment of spectro-temporal modulations sensitivity can evaluate the listener's ability to retrieve and integrate speech segments covered by noise. Therefore, the purpose of this study was to examine spectro-temporal modulation (STM) detection and its relation to speech perception in children with APD and to compare the results with aged-matched normally developed children.

METHODS

35 children with APD and 32 normal hearing children (8-12 years old) were enrolled. In order to examine STM detection performance, six different STM stimulus conditions were employed using three different temporal modulation rates (4, 12 and 32 Hz) and two different spectral modulation densities (0.5 and 2.0 cycles/octave). Initially, the STM detection thresholds at these six STM stimulus conditions were measured in both groups and the results were compared. Thereafter, the relation between STM detection thresholds and speech perception tests, including consonant-vowel in noise and word in noise tests were assessed.

RESULTS

The STM sensitivity was poorer than normal for APD children at all STM stimulus conditions. Children with APD displayed significantly poorer STM detection thresholds than those of normally developed children (p < 0.05). Significant correlations were found between STM detection thresholds and speech perception in noise in both groups (p < 0.05).

CONCLUSION

The results suggest that the altered encoding of spectro-temporal acoustic cues in the auditory nervous system may be one of the underlying factors of reduced STM detection performance in children with APD. The present study may suggest that poor ability to extract STM cues in children with APD, can be an underlying factor for their listening problems in noise and poor speech perception in challenging situations.

Speech-evoked auditory brainstem response; electrophysiological evidence of upper brainstem facilitative role on sound lateralization in noise

BACKGROUND AND AIM

Sound lateralization/localization is one of the most important auditory processing abilities, which plays approved role in auditory streaming and speech perception in challenging situations like noisy places. In addition to the main role of lower brainstem centers like superior olivary complex in sound lateralization, efferent auditory system effects on improving auditory skills in everyday auditory challenging positions were revealed. This study evaluated noise effects on lateralization scores in correlation with an objective electrophysiologic test (Speech-ABR in noise), which objectively shows cumulative effects of the afferent and efferent auditory systems at the inferior colliculus and upper brainstem pathway.

METHOD

Fourteen normal-hearing subjects in the age range of 18 to 25 participated in this study. Lateralization scores in the quiet and noisy modes were evaluated. Speech-ABR in both ears for quiet mode and three different contralateral noise levels (SNR = + 5, 0, - 5) were recorded, too. Correlation of lateralization scores and Speech-ABR changes in noise was studied.

RESULTS

Significant decrease of lateralization scores with latency increase and amplitude decrease of Speech-ABR transient peaks (V, A, O) was seen with noise presentation. A high positive correlation between lateralization decrease with latency increase of onset peaks (V, A) and amplitude decrease of transient peaks (V, A, O) was found in low signal-to-noise ratios.

CONCLUSION

The study revealed that in high challenging auditory situations like auditory lateralization in noise, upper brainstem centers and pathways play a facilitative role for main auditory lateralization centers in lower levels.

Correlation between Auditory Spectral Resolution and Speech Perception in Children with Cochlear Implants

Background:

Variability in speech performance is a major concern for children with cochlear implants (CIs). Spectral resolution is an important acoustic component in speech perception. Considerable variability and limitations of spectral resolution in children with CIs may lead to individual differences in speech performance. The aim of this study was to assess the correlation between auditory spectral resolution and speech perception in pediatric CI users.

Methods:

This cross-sectional study was conducted in Shiraz, Iran, in 2017. The frequency discrimination threshold (FDT) and the spectral-temporal modulated ripple discrimination threshold (SMRT) were measured for 75 pre-lingual hearing-impaired children with CIs (age=8-12 y). Word recognition and sentence perception tests were completed to assess speech perception. The Pearson correlation analysis and multiple linear regression analysis were used to determine the correlation between the variables and to determine the predictive variables of speech perception, respectively.

Results:

There was a significant correlation between the SMRT and word recognition (r=0.573 and P<0.001). The FDT was significantly correlated with word recognition (r=0.487 and P<0.001). Sentence perception had a significant correlation with the SMRT and the FDT. There was a significant correlation between chronological age and age at implantation with SMRT but not the FDT.

Conclusion:

Auditory spectral resolution correlated well with speech perception among our children with CIs. Spectral resolution ability accounted for approximately 40% of the variance in speech perception among the children with CIs.

Tinnitus induction in animals and its impact on auditory system structure

Background and Aim: Tinnitus is a perception of sound in ears or head in the absence of any external stimuli. Despite its high prevalence in various age groups, tinnitus has still no effective treatment because its physiological and patho­logical mechanisms have remained unknown. Since the study of cellular-molecular mechan­isms of tinnitus production and stability in human is not feasible, animal models have been used to shed some light on tinnitus induction and propagation mechanisms. This study revie­wed some of these research studies. The present review article is based on articles published during 1967–2018 in which keywords such as “salicylate,” “noise,” “tinnitus in the animal model,” and “tinnitus mechanism” were used. These articles were searched in databases such as Science Direct, Google Scholar, PubMed, and Scopus. Recent Findings: Despite differences in the mechanisms of tinnitus induction, the structural changes initiated from the cochlea and conti­nued to cortex reflect the extent of the affected regions in the creation, development, and pre­servation of tinnitus. Conclusion: Animal models (exposed to noise or ototoxic drugs such as salicylate) are ideal tools for studying tinnitus and understanding the details of its propagation and unknown mecha­nisms.

Efficacy of auditory training in older adults by electrophysiological tests

Background and Aim: Most elderly people in noisy environments complain of speech com­prehension. At present, hearing aids or cochlear implants are the main treatment options. How­ever, these devices merely enhance sound audi­bility and do not compensate for central pro­cessing changes caused by aging, hearing loss, or cognitive decline. This article reviewed plas­ticity topic in the auditory system and the use of auditory evoked potentials to prove the effec­tiveness of auditory training. Recent Findings: The search for relevant articles in the Google Scholar, PubMed, Springer, and ProQuest databases was con­ducted with the keywords of “auditory edu­cation,” “electrophysiology,” “plasticity,” and “aging.” A total of 107 articles were found with these keywords, and finally, 98 articles, pub­lished between 1977 and 2018, were used. Existence of plasticity in the central auditory system, regardless of age, has been proven. Therefore, cognitive and auditory training to reduce cognitive problems and improve central hearing processing in appropriate cases can positively affect the quality of hearing and social communication of the elderly. Because efficacy is an important component of any therapeutic approach, the assessment of the benefits of hearing training can be demonstrated by electrophysiological tests. Conclusion: Auditory training may play an important role in the elderly treatment program with speech perception defects. The usefulness of this rehabilitation can be objectively eva­luated through cortical and subcortical elec­trophysiological methods.

The impact of music on auditory and speech processing

Background and Aim: Researchers in the fields of psychoacoustic and electrophysiology are mostly focused on demonstrating the better and different neurophysiological performance of musicians. The present study explores the imp­act of music upon the auditory system, the non-auditory system as well as the improvement of language and cognitive skills following listening to music or receiving music training. Recent Findings: Studies indicate the impact of music upon the auditory processing from the cochlea to secondary auditory cortex and other parts of the brain. Besides, the impact of music on speech perception and other cognitive proce­ssing is demonstrated. Some papers point to the bottom-up and some others to the top-down pro­cessing, which is explained in detail. Conclusion: Listening to music and receiving music training, in the long run, creates plasticity from the cochlea to the auditory cortex. Since the auditory path of musical sounds overlaps functionally with that of speech path, music hel­ps better speech perception, too. Both percep­tual and cognitive functions are involved in this process. Music engages a large area of the brain, so music can be used as a supplement in rehabi­litation programs and helps the improvement of speech and language skills.

Binaural hearing advantages for children with bimodal fitting

OBJECTIVES

Bimodal fitting (BF) allows children with cochlear implant to benefit from binaural hearing advantages. Three major binaural hearing advantages, which enhance hearing function of people with normal hearing, are head shadow effect (HSE), binaural squelch effect (BSQ) and binaural summation effect (BSU). This study in pediatric patients attempting to measure the auditory benefits of bimodal stimulation in children with long-standing use of a cochlear implant (CI), and residual hearing on the contralateral side.

METHODS

This cross-sectional study investigated binaural advantages in 24 children of 8-12 years who had undergone cochlear implantation in a cochlear implant center in Tehran and continuously used BF. Improved score of speech perception in noise (SPiN) under BF condition, as compared to the application of cochlear implant alone, was a binaural advantage found in this study. Each binaural advantage was measured by obtaining the SPiN score under different listening and noise conditions, using relevant formulas. The measured value of each advantage reflects the improved score of SPiN, caused by that certain advantage.

RESULTS

In this study, improved mean SPiN score caused by the HSE, BSQ and BSU was, respectively, 3.13, 1.42 and 2.04 dB, indicating greater binaural advantages and hence improved SPiN, under BF condition in comparison with cochlear implant alone.

CONCLUSION

Children with unilateral cochlear implant and measurable residual hearing in non-implanted ear can benefit from binaural advantages and better SPiN when hearing aid is used in the unaided ear.

Speech-evoked auditory brainstem response: a review of stimulation and acquisition parameters

Background and Aim: Speech-auditory brain­stem response (ABR) as a new test in the field of auditory electrophysiology, examines the auditory processing of stimuli with complex acoustic structures at the subcortical level. In recent years, speech-ABR has been admini­stered to patients with various hearing impair­ments and people with special auditory skills. Results of these studies are of great interest to researchers in the fields of cognitive and audi­tory neurosciences. In this study, because of the increasing use of this test, a review of the stu­dies carried out on the origin of this response and the proposed protocols to stimulate, record, and analyze this electrophysiological response are presented. Recent Findings: The most common stimulus parameters used in the published articles was /da/ stimulus in 40 ms duration and 60-85 dB SPL intensity with the use of alternative polarity and rate of about 10 stimuli per second. The verified and widely-used acquisition parameters include using vertical electrode array with 6000 sweeps and a 30-3000 Hz filtering in a 60-70 ms time window. Conclusion: In determining the stimulus-record parameters of the speech-ABR test, in addition to considering the necessary minimums, the final values should always be selected based on the objectives and the study group. The unique features of this test for diagnosis and monitoring of auditory processing at supra-threshold levels, calls for comprehensive studies to formulate guidelines for the application of this test in aud­itory clinics but the basic points mentioned in this paper should be considered in the selection of each parameter.

Vestibular contribution to memory processing

Background and Aim: The vestibular system contributes in the stabilization of the head and body, orientation, and gazing through the pro­cessing of sensory inputs. A wealth of evidence supports the involvement of vestibular informa­tion in higher functions, too.Methods: In this paper, we reviewed the pre­vious studies on the effect of the vestibular sys­tem on memory as one of the cognitive func­tions.Results: Clinical and laboratory findings indi­cate the association of vestibular inputs (besides postural control and oculomotor) with a variety of higher functions, especially memory func­tion. Because part of the memory function is determined by other cognitive processes i.e. att­ention capacity, emotional disturbances, and executive functions, the study of the effect of vestibular inputs on these functions provides a more accurate view of how the vestibular inputs affect memory performance.Conclusion: Although our current knowledge on vestibular-memory interaction is increasing, the exact involvement of vestibular signals in memory representations is still unclear and needs further studies to determine the theore­tical basis of vestibular involvement in memory processing.

Auditory processing and auditory rehabilitation approaches in autism

Background and Aim: Concerning the preva­lence of autism spectrum disorder, many studies have examined the various aspects of this dis­order. One of the major problems in autism is the sensory processing deficit, and in particular the abnormalities of auditory processing. In this review article, we have tried to explain the neu­rological features of auditory processing and abnormalities in auditory evoked responses in autism, finally recount some of the main met­hods of auditory rehabilitation. Recent Findings: We searched for articles in databases with keywords of “autism,” “auditory processing” and “auditory rehabilitation.” A total of 102 articles were initially found in this field. Some articles were not about our study topic, thus in the end, only 79 articles were ent­ered the study published from 1989 to 2018. Based on these studies, autism associates with a weakness in sensory integration due to abnor­mal interactions between different neural net­works. This condition of auditory modality are being manifested as different abnormalities in evoked responses, especially for complex sti­muli at the level of the brainstem and cortex. Language and speech problems are prevalent in many patients with autism, which has already been mentioned in numerous studies. To treat these deficits, appropriate auditory rehabilitation techniques (often using music to improve the symptoms) have been developed. Conclusion: In order to know more about aut­ism and adopt appropriate interventions, doing audiometric, behavioral and electrophysiologi­cal evaluations are recommended on a regular basis. Rehabilitation in this disorder generally include music therapy, signal-to-noise enhanc­ement strategies, and cognitive behavioral the­rapies.

Binaural sensitivity to temporal fine structure and lateralization ability in children with suspected (central) auditory processing disorder

OBJECTIVE

Previous studies have shown that a subgroup of children with suspected (central) auditory processing disorder (SusCAPD) have insufficient ability to use binaural cues to benefit from spatial processing. Thus, they experience considerable listening difficulties in challenging auditory environments, such as classrooms. Some researchers have also indicated the probable role of binaural temporal fine structure (TFS) in the perceptual segregation of target signal from noise and hence in speech perception in noise. Therefore, in the present study, in order to further investigate the underlying reason for listening problems against background noise in this group of children, their performance was measured using binaural TFS sensitivity test (TFS-LF) as well as behavioral auditory lateralization in noise test, both of which are based on binaural temporal cues processing.

METHODS

Participants in this analytical study included 91 children with normal hearing and no listening problems and 41 children (9-12 years old) with SusCAPD who found it challenging to understand speech in noise. Initially, the ability to use binaural TFS was measured at three frequencies (250, 500 and 750Hz) in both the groups, and the results of preliminary evaluations were compared between normal children and those with SusCAPD who participated in the study. Thereafter, the binaural performance of the 16 children with SusCAPD who had higher thresholds than the normal group at all three frequencies tested in TFS-LF test was examined using the lateralization test in 7 spatial locations.

RESULTS

Total 16 of the 41 children with SusCAPD who participated in this study (39%) showed poor performance on the TFS-LF test at all three frequencies, compared to both normal children and other children in the APD group (p<0.05). Furthermore, children in the APD group with binaural TFS coding deficits at all three frequencies revealed significant differences in the lateralization test results compared to normal children (p<0.05).

CONCLUSION

Findings of the current study demonstrated that one of the underlying causes for the difficulty understanding speech in noisy environments experienced by a subgroup of children with SusCAPD can be the reduced ability to benefit from binaural TFS information. This study also showed that a reduced ability to use binaural TFS cues in the group of children with SusCAPD was accompanied by reduced binaural processing abilities in the lateralization test which also admit the presence of binaural temporal processing deficits in this group of children.

Effects of Age on Speech-in-Noise Identification: Subjective Ratings of Hearing Difficulties and Encoding of Fundamental Frequency in Older Adults

Background and Objectives

Numerous studies have indicated deterioration of speech perception in noisy conditions among the elderly even those with normal hearing capabilities. The aim of this study was to investigate the effects of age on the speech-in-noise identification by speech-in-noise (SIN) test, subjective ratings of hearing difficulties by speech, spatial, and qualities of hearing scale (SSQ) questionnaire and encoding of fundamental frequency (F₀) by Speech auditory brainstem response (ABR) in the elderly and comparing the results with young people.

Subjects and Methods

The present study was conducted on 32 elderly people aged over 60 years old (17 male and 15 female) with the mean age of 68.9 (standard deviation=6.33) possessing normal peripheral hearing and 32 young subjects (16 male and 16 female) aged 18-25 years old.

Results

Findings showed that the score of SIN test is lower among the elderly people as compared with young people in signal-to-noise ratios of 0 and -10 based on Iranian version of SSQ questionnaire (p<0.001). The range of F₀ amplitude in the elderly people is also lower than young people (p<0.001) in Speech ABR.

Conclusions

It seems that speech processing in older people is deteriorated comparing with young people regardless of their normal peripheral auditory thresholds. This decrease will result in weaker perception and improper segregation of speech from other competing sources.

Brainstem Correlates of Comodulation Masking Release for Speech in Normal Hearing Adults

Background and Objectives

Weak signals embedded in fluctuating masker can be perceived more efficiently than similar signals embedded in unmodulated masker. This release from masking is known as comodulation masking release (CMR). In this paper, we investigate, neural correlates of CMR in the human auditory brainstem.

Subjects and Methods

A total of 26 normal hearing subjects aged 18-30 years participated in this study. First, the impact of CMR was quantified by a behavioral experiment. After that, the brainstem correlates of CMR was investigated by the auditory brainstem response to complex sounds (cABR) in comodulated (CM) and unmodulated (UM) masking conditions.

Results

The auditory brainstem responses are less susceptible to degradation in response to the speech syllable /da/ in the CM noise masker in comparison with the UM noise masker. In the CM noise masker, frequency-following response (FFR) and fundamental frequency (F0) were correlated with better behavioral CMR. Furthermore, the subcortical response timing of subjects with higher CMR was less affected by the CM noise masker, having higher stimulus-to-noise response correlations over the FFR range.

Conclusions

The results of the present study revealed a significant link between brainstem auditory processes and CMR. The findings of the present study show that cABR provides objective information about the neural correlates of CMR for speech stimulus.

Reliability of Interaural Time Difference-Based Localization Training in Elderly Individuals with Speech-in-Noise Perception Disorder

BACKGROUND

Previous studies have shown that interaural-time-difference (ITD) training can improve localization ability. Surprisingly little is, however, known about localization training vis-à-vis speech perception in noise based on interaural time difference in the envelope (ITD ENV). We sought to investigate the reliability of an ITD ENV-based training program in speech-in-noise perception among elderly individuals with normal hearing and speech-in-noise disorder.

METHODS

The present interventional study was performed during 2016. Sixteen elderly men between 55 and 65 years of age with the clinical diagnosis of normal hearing up to 2000 Hz and speech-in-noise perception disorder participated in this study. The training localization program was based on changes in ITD ENV. In order to evaluate the reliability of the training program, we performed speech-in-noise tests before the training program, immediately afterward, and then at 2 months' follow-up. The reliability of the training program was analyzed using the Friedman test and the SPSS software.

RESULTS

Significant statistical differences were shown in the mean scores of speech-in-noise perception between the 3 time points (P=0.001). The results also indicated no difference in the mean scores of speech-in-noise perception between the 2 time points of immediately after the training program and 2 months' follow-up (P=0.212).

CONCLUSION

The present study showed the reliability of an ITD ENV-based localization training in elderly individuals with speech-in-noise perception disorder.

Study of the effects of hearing on static and dynamic postural function in children using cochlear implants

OBJECTIVE

The present study aimed to evaluate the postural control perturbations by the center of pressure parameters in two main approaches, cochlear implant turned "on" and "off".

METHODS

We included 25 children aged 8-10 years with unilateral cochlear implants and bilateral vestibular hypofunction deficit. To evaluate the postural function, each children was asked to stand on the force plate under 3 different conditions and cochlear implant turned "on" and "off": Condition (A) double stance from open eyes to closed eyes, Condition (B) double stance with open eyes engaging in the dual task and Condition (C) From double leg stance to one leg stance with open eyes for assessment of dynamic postural control. Also to calculate the center of pressure parameters, we designed new software for the force plate RESULTS: In condition A: although the results demonstrated an overall reduction in the mean of center of pressure parameters when the cochlear implant was "on", only the significant differences were seen in mean and standard deviations for anterior-posterior displacement, mediolateral displacement, area and mean velocity (P =0.00, P=0.04, P=0.02 and P=0.00, respectively) in open eyes In condition B: no significant difference was found between "on" and "off" cochlear implant in single or dual-task situations. In condition C: mean velocity variable demonstrated a significant difference (P=0.00) in the cochlear implant "on" condition in double leg stance only. Also, anterior-posterior displacement demonestrated a significant difference (P=0.00) when the cochlear implant was turned "on" in one leg stance situation.

CONCLUSION

The results of our study show that auditory information can improve postural stability and reduce body sways in different situations as an underlying system for reinforcement of the postural control in children without complete normal balance subsystems.

Musical Training Enhances Neural Processing of Comodulation Masking Release in the Auditory Brainstem

Musical training strengthens segregation the target signal from background noise. Musicians have enhanced stream segregation, which can be considered a process similar to comodulation masking release. In the current study, we surveyed psychoacoustical comodulation masking release in musicians and non-musicians. We then recorded the brainstem responses to complex stimuli in comodulated and unmodulated maskers to investigate the effect of musical training on the neural representation of comodulation masking release for the first time. The musicians showed significantly greater amplitudes and earlier brainstem response timing for stimulus in the presence of comodulated maskers than non-musicians. In agreement with the results of psychoacoustical experiment, musicians showed greater comodulation masking release than non-musicians. These results reveal a physiological explanation for behavioral enhancement of comodulation masking release and stream segregation in musicians.

Envelope-based inter-aural time difference localization training to improve speech-in-noise perception in the elderly

Background: Many elderly individuals complain of difficulty in understanding speech in noise despite having normal hearing thresholds. According to previous studies, auditory training leads to improvement in speech-in-noise perception, but these studies did not consider the etiology, so their results cannot be generalized. The present study aimed at investigating the effectiveness of envelopebased interaural time difference (ITD ENV) localization training on improving ITD threshold and speech-in-noise perception. Methods: Thirty-two elderly males aged 55 to 65 years with clinically diagnosed normal hearing at 250-2000 Hertz, who suffered from speech-in-noise perception difficulty participated in this study. These individuals were randomly divided into training and control groups: 16 elderlies in the experimental group received envelope-based interaural time difference localization training in 9 sessions, but 16 matched elderlies in the control group did not receive any training. The ITD ENV threshold and spatial word recognition score (WRS) in noise were analyzed before and after the localization training. Results: Findings demonstrated that following the training program, the interaural time difference envelope threshold and spatial word recognition score (WRS) in noise were improved significantly in the experimental group (p≤ 0.001). Moreover, a significant difference was detected in interaural time difference envelope threshold and spatial word recognition score (WRS) in noise (p≤ 0.001) before and after the training in the experimental group. Conclusion: The results of the present study revealed the effectiveness of envelope- based interaural time difference localization training in localization ability and speech in noise perception in the elderlies with normal hearing up to 2000 Hz who suffered from speech-in-noise perception difficulty.

Relation between Working Memory Capacity and Auditory Stream Segregation in Children with Auditory Processing Disorder

BACKGROUND

This study assessed the relationship between working memory capacity and auditory stream segregation by using the concurrent minimum audible angle in children with a diagnosed auditory processing disorder (APD).

METHODS

The participants in this cross-sectional, comparative study were 20 typically developing children and 15 children with a diagnosed APD (age, 9-11 years) according to the subtests of multiple-processing auditory assessment. Auditory stream segregation was investigated using the concurrent minimum audible angle. Working memory capacity was evaluated using the non-word repetition and forward and backward digit span tasks. Nonparametric statistics were utilized to compare the between-group differences. The Pearson correlation was employed to measure the degree of association between working memory capacity and the localization tests between the 2 groups.

RESULTS

The group with APD had significantly lower scores than did the typically developing subjects in auditory stream segregation and working memory capacity. There were significant negative correlations between working memory capacity and the concurrent minimum audible angle in the most frontal reference location (0° azimuth) and lower negative correlations in the most lateral reference location (60° azimuth) in the children with APD.

CONCLUSION

The study revealed a relationship between working memory capacity and auditory stream segregation in children with APD. The research suggests that lower working memory capacity in children with APD may be the possible cause of the inability to segregate and group incoming information.

Concurrent auditory perception difficulties in older adults with right hemisphere cerebrovascular accident

BACKGROUND

Older adults with cerebrovascular accident (CVA) show evidence of auditory and speech perception problems. In present study, it was examined whether these problems are due to impairments of concurrent auditory segregation procedure which is the basic level of auditory scene analysis and auditory organization in auditory scenes with competing sounds.

METHODS

Concurrent auditory segregation using competing sentence test (CST) and dichotic digits test (DDT) was assessed and compared in 30 male older adults (15 normal and 15 cases with right hemisphere CVA) in the same age groups (60-75 years old). For the CST, participants were presented with target message in one ear and competing message in the other one. The task was to listen to target sentence and repeat back without attention to competing sentence. For the DDT, auditory stimuli were monosyllabic digits presented dichotically and the task was to repeat those.

RESULTS

Comparing mean score of CST and DDT between CVA patients with right hemisphere impairment and normal participants showed statistically significant difference (p=0.001 for CST and p<0.0001 for DDT).

CONCLUSION

The present study revealed that abnormal CST and DDT scores of participants with right hemisphere CVA could be related to concurrent segregation difficulties. These findings suggest that low level segregation mechanisms and/or high level attention mechanisms might contribute to the problems.

The relation between working memory capacity and auditory lateralization in children with auditory processing disorders

OBJECTIVE

Auditory processing disorder (APD) describes a complex and heterogeneous disorder characterized by poor speech perception, especially in noisy environments. APD may be responsible for a range of sensory processing deficits associated with learning difficulties. There is no general consensus about the nature of APD and how the disorder should be assessed or managed. This study assessed the effect of cognition abilities (working memory capacity) on sound lateralization in children with auditory processing disorders, in order to determine how "auditory cognition" interacts with APD.

METHODS

The participants in this cross-sectional comparative study were 20 typically developing and 17 children with a diagnosed auditory processing disorder (9-11 years old). Sound lateralization abilities investigated using inter-aural time (ITD) differences and inter-aural intensity (IID) differences with two stimuli (high pass and low pass noise) in nine perceived positions. Working memory capacity was evaluated using the non-word repetition, and forward and backward digits span tasks. Linear regression was employed to measure the degree of association between working memory capacity and localization tests between the two groups.

RESULTS

Children in the APD group had consistently lower scores than typically developing subjects in lateralization and working memory capacity measures. The results showed working memory capacity had significantly negative correlation with ITD errors especially with high pass noise stimulus but not with IID errors in APD children.

CONCLUSIONS

The study highlights the impact of working memory capacity on auditory lateralization. The finding of this research indicates that the extent to which working memory influences auditory processing depend on the type of auditory processing and the nature of stimulus/listening situation.

Effects of vowel auditory training on concurrent speech segregation in hearing impaired children

OBJECTIVE

This clinical trial investigated the ability of concurrent speech segregation in hearing impaired children. The auditory behavioral responses and auditory late responses (ALRs) were compared between test and control groups prior to vowel auditory training and after 3 and 6 months of vowel auditory training to find the effects of bottom-up training on concurrent speech segregation in hearing impaired children.

METHODS

Auditory behavioral responses for 5 vowels and ALRs for double synthetic vowels, with special physical properties, were recorded in a timetable in 30 hearing impaired children (test group = 15 and control group = 15).

RESULTS

Identification score and reaction time data showed that the test group was approximately proficient for some vowels (P < .05 for vowels /æ/, /e/, and /u:/) and took less time to process after 6 months of training. N1-P2 amplitude indexing of the vowel change detection and reflecting central auditory speech representation without active client participation has been increased in the test group (P < .05).

CONCLUSION

The present study showed training-related improvements in concurrent speech segregation. This information provided evidence for bottom-up training based on F0, its differences in auditory scene analysis, and neural underpinnings.

Quality of life improvement in hearing-impaired elderly people after wearing a hearing aid

BACKGROUND

Communication is an important aspect of everyday life especially for elderly people. Hearing loss can impair the exchange of information and therefore reduces the quality of life. The purpose of this study was to investigate the quality of life in elderly people who are hard of hearing after wearing a hearing aid.

METHODS

Hearing-impaired old people who referred to the rehabilitation centers of Tehran Welfare Organization for having a hearing aid completed the Hearing Handicap Inventory for the Elderly questionnaire before and three months after using a hearing aid. Scores of the effects of hearing loss on quality of life were compared for each subject and between males and females.

RESULTS

The results showed a significant improvement of the quality of life after three months of using a hearing aid in all participants and betterment of their most important problems i.e., the communication and exchange of information.

CONCLUSION

In conclusion, with respect to the beneficial effects of hearing aids in presbycusis and due to the significant improvement in the quality of life, hearing aids are recommended for this group of population.