Dichotic word recognition in noise and the right-ear advantage

Spatial Hearing in Children With and Without Hearing Loss: Where and What the Speech Is Matters for Local Speech Intelligibility

PURPOSE

This study examined children's ability to perceive speech from multiple locations on the horizontal plane. Children with hearing loss were compared to normal-hearing peers while using amplification with and without advanced noise management.

METHOD

Participants were 21 children with normal hearing (9-15 years) and 12 children with moderate symmetrical hearing loss (11-15 years). Word recognition, nonword detection, and word recall were assessed. Stimuli were presented randomly from multiple discrete locations in multitalker noise. Children with hearing loss were fit with devices having separate omnidirectional and noise management programs. The noise management feature is designed to preserve audibility in noise by rapidly analyzing input from all locations and reducing the noise management when speech is detected from locations around the hearing aid user.

RESULTS

Significant effects of left/right and front/back lateralization occurred as well as effects of hearing loss and hearing aid noise management. Children with normal hearing experienced a left-side advantage for word recognition and a right-side advantage for nonword detection. Children with hearing loss demonstrated poorer performance overall on all tasks with better word recognition from the back, and word recall from the right, in the omnidirectional condition. With noise management, performance improved from the front compared to the back for all three tasks and from the right for word recognition and word recall.

CONCLUSIONS

The shape of children's local speech intelligibility on the horizontal plane is not omnidirectional. It is task dependent and shaped further by hearing loss and hearing aid signal processing. Front/back shifts in children with hearing loss are consistent with the behavior of hearing aid noise management, while the right-side biases observed in both groups are consistent with the effects of specialized speech processing in the left hemisphere of the brain.

Subjective tinnitus patients with normal pure-tone hearing still suffer more informational masking in the noisy environment

Subjective tinnitus patients experience more hearing difficulties than normal peers in complex hearing environments, even though most of these patients have normal pure-tone hearing thresholds. Using speech recognition tasks under different masking conditions can provide insight into whether the effects of tinnitus are lateralized and the mechanisms behind the effects. By simulating sound field recordings, we obtain a target speech sentence that can be perceived as presented on one side and noise or speech masking with or without spatial separation from it. Our study used the virtual sound field technique to investigate the difference in speech recognition ability between chronic subjective tinnitus patients and a normal-hearing control group under the four masking conditions (speech-spectrum noise masking or two-talker speech masking, with or without perceived spatial separation). Experiment 1 showed no differences for target speech perceived location (left or right), which rules out a lateralization of the effect of tinnitus patients. Experiment 2 further found that although tinnitus patients had weaker performance than normal people in very complex auditory scenarios, when the spatial cue of the target speech exists, they can make good use of this cue to make up for the original processing disadvantage and achieve a similar performance as the normal-hearing group. In addition, the current study distinguished the effects of informational masking and energetic masking on speech recognition in patients with tinnitus and normal hearing. The results suggest that the impact of tinnitus on speech recognition in patients is more likely to occur in the auditory center rather than the periphery.

Speech Perception in Older Adults: An Interplay of Hearing, Cognition, and Learning?

Older adults with age-related hearing loss exhibit substantial individual differences in speech perception in adverse listening conditions. We propose that the ability to rapidly adapt to changes in the auditory environment (i.e., perceptual learning) is among the processes contributing to these individual differences, in addition to the cognitive and sensory processes that were explored in the past. Seventy older adults with age-related hearing loss participated in this study. We assessed the relative contribution of hearing acuity, cognitive factors (working memory, vocabulary, and selective attention), rapid perceptual learning of time-compressed speech, and hearing aid use to the perception of speech presented at a natural fast rate (fast speech), speech embedded in babble noise (speech in noise), and competing speech (dichotic listening). Speech perception was modeled as a function of the other variables. For fast speech, age [odds ratio (OR) = 0.79], hearing acuity (OR = 0.62), pre-learning (baseline) perception of time-compressed speech (OR = 1.47), and rapid perceptual learning (OR = 1.36) were all significant predictors. For speech in noise, only hearing and pre-learning perception of time-compressed speech were significant predictors (OR = 0.51 and OR = 1.53, respectively). Consistent with previous findings, the severity of hearing loss and auditory processing (as captured by pre-learning perception of time-compressed speech) was strong contributors to individual differences in fast speech and speech in noise perception. Furthermore, older adults with good rapid perceptual learning can use this capacity to partially offset the effects of age and hearing loss on the perception of speech presented at fast conversational rates. Our results highlight the potential contribution of dynamic processes to speech perception.

Effects of the Configuration of Hearing Loss on Consonant Perception between Simulated Bimodal and Electric Acoustic Stimulation Hearing

BACKGROUND

 Cochlear implant technology allows for acoustic and electric stimulations to be combined across ears (bimodal) and within the same ear (electric acoustic stimulation [EAS]). Mechanisms used to integrate speech acoustics may be different between the bimodal and EAS hearing, and the configurations of hearing loss might be an important factor for the integration. Thus, differentiating the effects of different configurations of hearing loss on bimodal or EAS benefit in speech perception (differences in performance with combined acoustic and electric stimulations from a better stimulation alone) is important.

PURPOSE

 Using acoustic simulation, we determined how consonant recognition was affected by different configurations of hearing loss in bimodal and EAS hearing.

RESEARCH DESIGN

 A mixed design was used with one between-subject variable (simulated bimodal group vs. simulated EAS group) and one within-subject variable (acoustic stimulation alone, electric stimulation alone, and combined acoustic and electric stimulations).

STUDY SAMPLE

 Twenty adult subjects (10 for each group) with normal hearing were recruited.

DATA COLLECTION AND ANALYSIS

 Consonant perception was unilaterally or bilaterally measured in quiet. For the acoustic stimulation, four different simulations of hearing loss were created by band-pass filtering consonants with a fixed lower cutoff frequency of 100 Hz and each of the four upper cutoff frequencies of 250, 500, 750, and 1,000 Hz. For the electric stimulation, an eight-channel noise vocoder was used to generate a typical spectral mismatch by using fixed input (200-7,000 Hz) and output (1,000-7,000 Hz) frequency ranges. The effects of simulated hearing loss on consonant recognition were compared between the two groups.

RESULTS

 Significant bimodal and EAS benefits occurred regardless of the configurations of hearing loss and hearing technology (bimodal vs. EAS). Place information was better transmitted in EAS hearing than in bimodal hearing.

CONCLUSION

 These results suggest that configurations of hearing loss are not a significant factor for integrating consonant information between acoustic and electric stimulations. The results also suggest that mechanisms used to integrate consonant information may be similar between bimodal and EAS hearing.

Right-Ear Advantage for Speech-in-Noise Recognition in Patients with Nonlateralized Tinnitus and Normal Hearing Sensitivity

Despite having normal hearing sensitivity, patients with chronic tinnitus may experience more difficulty recognizing speech in adverse listening conditions as compared to controls. However, the association between the characteristics of tinnitus (severity and loudness) and speech recognition remains unclear. In this study, the Quick Speech-in-Noise test (QuickSIN) was conducted monaurally on 14 patients with bilateral tinnitus and 14 age- and hearing-matched adults to determine the relation between tinnitus characteristics and speech understanding. Further, Tinnitus Handicap Inventory (THI), tinnitus loudness magnitude estimation, and loudness matching were obtained to better characterize the perceptual and psychological aspects of tinnitus. The patients reported low THI scores, with most participants in the slight handicap category. Significant between-group differences in speech-in-noise performance were only found at the 5-dB signal-to-noise ratio (SNR) condition. The tinnitus group performed significantly worse in the left ear than in the right ear, even though bilateral tinnitus percept and symmetrical thresholds were reported in all patients. This between-ear difference is likely influenced by a right-ear advantage for speech sounds, as factors related to testing order and fatigue were ruled out. Additionally, significant correlations found between SNR loss in the left ear and tinnitus loudness matching suggest that perceptual factors related to tinnitus had an effect on speech-in-noise performance, pointing to a possible interaction between peripheral and cognitive factors in chronic tinnitus. Further studies, that take into account both hearing and cognitive abilities of patients, are needed to better parse out the effect of tinnitus in the absence of hearing impairment.

The performance of an automatic acoustic-based program classifier compared to hearing aid users' manual selection of listening programs

OBJECTIVE

To compare preference for and performance of manually selected programmes to an automatic sound classifier, the Phonak AutoSense OS.

DESIGN

A single blind repeated measures study. Participants were fit with Phonak Virto V90 ITE aids; preferences for different listening programmes were compared across four different sound scenarios (speech in: quiet, noise, loud noise and a car). Following a 4-week trial preferences were reassessed and the users preferred programme was compared to the automatic classifier for sound quality and hearing in noise (HINT test) using a 12 loudspeaker array.

STUDY SAMPLE

Twenty-five participants with symmetrical moderate-severe sensorineural hearing loss.

RESULTS

Participant preferences of manual programme for scenarios varied considerably between and within sessions. A HINT Speech Reception Threshold (SRT) advantage was observed for the automatic classifier over participant's manual selection for speech in quiet, loud noise and car noise. Sound quality ratings were similar for both manual and automatic selections.

CONCLUSIONS

The use of a sound classifier is a viable alternative to manual programme selection.

Association between language development and auditory processing disorders1

Introduction

It is crucial to understand the complex processing of acoustic stimuli along the auditory pathway; comprehension of this complex processing can facilitate our understanding of the processes that underlie normal and altered human communication.

Aim

To investigate the performance and lateralization effects on auditory processing assessment in children with specific language impairment (SLI), relating these findings to those obtained in children with auditory processing disorder (APD) and typical development (TD).

Material and methods

Prospective study. Seventy-five children, aged 6-12 years, were separated in three groups: 25 children with SLI, 25 children with APD, and 25 children with TD. All went through the following tests: speech-in-noise test, Dichotic Digit test and Pitch Pattern Sequencing test.

Results

The effects of lateralization were observed only in the SLI group, with the left ear presenting much lower scores than those presented to the right ear. The inter-group analysis has shown that in all tests children from APD and SLI groups had significantly poorer performance compared to TD group. Moreover, SLI group presented worse results than APD group.

Conclusion

This study has shown, in children with SLI, an inefficient processing of essential sound components and an effect of lateralization. These findings may indicate that neural processes (required for auditory processing) are different between auditory processing and speech disorders.