Implications of reduced frequency selectivity in cochlear impairment

Auditory temporal processing, reading, and phonological awareness among aging adults

Background and Aim: Many older adults experience difficulty in speech perception in noisy environments and fast speech. Speech perception is dependent on bottom-up and top-down auditory processing information. This study aimed to investigate the relationship between Interaural Time Difference (ITD) and speech processing speed in older adults with difficulty in speech perception in noise. Methods: In this study, 36 Iranian older adults with normal hearing (23 men and 13 women) aged 65–75 years who had complaints about the difficulty with speech perception in noise, participated. The ITD test with two stimuli (high-pass and low-pass noise) was used to asess the auditory localization ability. Time-Compressed Speech Test (TCST) and reaction time test were used to measure their speech processing speed. Pearson correlation test was performed to examine the relationship between ITD and speech processing speed. Results: The auditory localization errors were more significant for ITDs with low-pass noise than high-pass noise. The results showed a negative correlation between localization errors and the TCST score at time compression ratios of 40% (p=0.005) and 60% (p=0.002). The highest correlation was observed between ITD (low-pass noise) and the TCST score at the time compression ratio of 60% in the right ear (r=–0.66). The mean ITD errors were not significantly correlated to the reaction time test score (p>0.05). Conclusion: Word recognition in the elderly declines with increasing speech rate. The findings of this study can be used in clinical practice for consultation and rehabilitation of older adults with communication difficulties. Keywords: Sound localization; speed processing; speech perception; elderly

Speech production difficulties are apparent in people who stutter (PWS). PWS also have difficulties in speech perception compared to controls. It is unclear whether the speech perception difficulties in PWS are independent of, or related to, their speech production difficulties. To investigate this issue, functional MRI data were collected on 13 PWS and 13 controls whilst the participants performed a speech production task and a speech perception task. PWS performed poorer than controls in the perception task and the poorer performance was associated with a functional activity difference in the left anterior insula (part of the speech motor area) compared to controls. PWS also showed a functional activity difference in this and the surrounding area [left inferior frontal cortex (IFC)/anterior insula] in the production task compared to controls. Conjunction analysis showed that the functional activity differences between PWS and controls in the left IFC/anterior insula coincided across the perception and production tasks. Furthermore, Granger Causality Analysis on the resting-state fMRI data of the participants showed that the causal connection from the left IFC/anterior insula to an area in the left primary auditory cortex (Heschl’s gyrus) differed significantly between PWS and controls. The strength of this connection correlated significantly with performance in the perception task. These results suggest that speech perception difficulties in PWS are associated with anomalous functional activity in the speech motor area, and the altered functional connectivity from this area to the auditory area plays a role in the speech perception difficulties of PWS.

Temporal fine structure (TFS) sensitivity, frequency selectivity, and speech reception in noise were measured for young normal-hearing (NHY), old normal-hearing (NHO), and hearing-impaired (HI) subjects. Two measures of TFS sensitivity were used: the "TFS-LF test" (interaural phase difference discrimination) and the "TFS2 test" (discrimination of harmonic and frequency-shifted tones). These measures were not significantly correlated with frequency selectivity (after partialing out the effect of audiometric threshold), suggesting that insensitivity to TFS cannot be wholly explained by a broadening of auditory filters. The results of the two tests of TFS sensitivity were significantly but modestly correlated, suggesting that performance of the tests may be partly influenced by different factors. The NHO group performed significantly more poorly than the NHY group for both measures of TFS sensitivity, but not frequency selectivity, suggesting that TFS sensitivity declines with age in the absence of elevated audiometric thresholds or broadened auditory filters. When the effect of mean audiometric threshold was partialed out, speech reception thresholds in modulated noise were correlated with TFS2 scores, but not measures of frequency selectivity or TFS-LF test scores, suggesting that a reduction in sensitivity to TFS can partly account for the speech perception difficulties experienced by hearing-impaired subjects.

The nature and cause of auditory processing deficits in dyslexic individuals have been debated for decades. Auditory processing deficits were argued to be the first step in a causal chain of difficulties, leading to difficulties in speech perception and thereby phonological processing and literacy difficulties. More recently, it has been argued that auditory processing difficulties may not be causally related to language and literacy difficulties. This study compares two groups who have phonological processing impairments for different reasons: dyslexia and a history of otitis media (OM). We compared their discrimination thresholds and response variability to chronological age- and reading age-matched controls, across three auditory processing tasks: frequency discrimination, rise-time discrimination and speech perception. Dyslexic children showed raised frequency discrimination thresholds in comparison with age-matched controls but did not differ from reading age-matched controls or individuals with a history of OM. There were no group differences on speech perception or rise-time tasks. For the dyslexic children, there was an association between phonological awareness and frequency discrimination response variability, but no association with thresholds. These findings are not consistent with a 'causal chain' explanation but could be accounted for within a multiple deficits view of literacy difficulties.

Object: Selective auditory attention and speech perception in the presence of noise are necessary skills to correctly process speech. Persian version of monaural selective auditory attention test [P-mSAAT] that simultaneously assesses selective auditory attention and speech in noise perception performance was used in the present study.Design: The P-mSAAT was performed on 89 normal children aged 6 to 9 and 24 children with learning disability sampled from different schools in Tehran in two competitive and non-competitive ways.Results: The average of test scores had a significant difference in a competitive way between normal and children with learning disability (P < 0/001). Furthermore, the test scores improved as a function of age in the both groups.Conclusion: Findings of the current study demonstrated that children presented with learning disability had difficulty in speech perception in the presence of competitive noise accompanied by reduced selective auditory attention ability. It is also suggested that P-mSAAT can be used as a screening test in diagnosing Learning disability in children aged 6 to 9 due to its high sensitivity.

Background Language and culture-specific speech perception tests help in the assessment of children's linguistic proficiency and comprehension. Recognizing difficulties in speech perception and implementing interventions in challenging auditory conditions are pivotal for their holistic development. Objective The aim of this study was to develop a speech perception in noise test in Marathi using trisyllabic words for children between the age ranges of 3 and 6 years. Method The study was conducted in two phases. The first phase comprised the development of trisyllabic word recognition in noise test in Marathi and the second phase comprised administration of the test on 90 typically developing normal hearing children aged 3 to 6 years. These children were divided into three groups (group A: &gt;3–4 years; group B: &gt;4–5 years; and group C: &gt;5–6 years), with 30 participants in each group. Results As the signal-to-noise ratio (SNR) increases, children across different age range show an improvement in their speech perception scores. Also, young children require a more favorable SNR compared with older children to effectively comprehend speech in noisy conditions. Conclusion The Trisyllabic word recognition in noise test will help in optimizing classroom acoustics for typical developing and hearing-impaired children. An SNR-based evaluation can provide guidance regarding interventions, amplification decisions, and auditory training, ensuring effective education and communication for children with hearing impairment.

Developing an International Core Outcome Set for SSD Interventions

With aging, some alterations in the perception and detection of sound in the auditory system occur and have repercussions in the communication process. The study of older adult's hearing must include the evaluation of the peripheral and central auditory system with the adequacy of behavioral and electrophysiological techniques that include the evaluation of the Central Auditory Processing in order to implement auditory training programs. The auditory training can be applied in different age ranges and are an excellent option for individuals with hearing loss, auditory device users and older adult with difficulties in speech understanding. The objective of this study is to evaluate the effect of auditory training on older adult's capacities to understand speech. The population of the study was constituted by 16 subjects aged between 58 and 91 years old, divided into two groups in which the type of auditory training varied in order to evaluate the training influence. All the individuals revealed benefits with the auditory training, once the speech perception in noise showed statistically significant improvement. The auditory training will benefit subjects with hearing loss and difficulties in speech perception, minimizing the impact hearing loss has in older people's lives.

&lt;p style="text-align: justify;"&gt;&lt;span lang="EN-US"&gt;Objectives&lt;/span&gt;&lt;span lang="EN-US"&gt;. Children with Autism Spectrum Disorder (ASD) often face difficulties in speech perception, particularly in noisy environments. These problems are associated with central auditory processing disorders. FM systems, which improve the signal-to-noise ratio, can be used to enhance speech perception. The aim of this study was to investigate the effects of FM systems when working with children with ASD in noisy conditions and their use in a school setting. Methods. The pilot study was conducted in two stages. In the first stage, the &amp;ldquo;Words in Noise&amp;rdquo; test and the &amp;ldquo;Sentence Repetition&amp;rdquo; task were used to assess children&amp;rsquo;s ability to recognize speech in noisy conditions with and without the use of FM systems. Fourteen children with ASD and 14 typically developing peers participated in the experiment. In the second stage, FM systems were studied in real school environments with 10 elementary school students with autism. Changes in auditory abilities were assessed using the L.I.F.E.-R scale. Results. In the first stage, it was found that children with ASD recognized significantly fewer words in noisy conditions compared to their typically developing peers. In the &amp;ldquo;Sentence Repetition&amp;rdquo; task, the use of FM systems improved the performance of children with ASD from 58.3% to 76.9% (p=0.0005). In the second stage, most participants showed minimal changes in auditory ability scores on the L.I.F.E.-R scale: the average score before using FM systems was 54.9, and after using them it was 57&lt;/span&gt;&lt;span lang="EN-US"&gt;.4 (p=0.2322). However, several students showed improvements of 8&amp;ndash;13 points, reflecting individual variability in the effect of using FM systems. Discussion. FM systems have demonstrated their effectiveness in improving speech perception in noisy environments for children with ASD. However, the integration of FM systems into the school process requires further research on their effectiveness in real conditions, as well as adaptations to minimize discomfort for children and improve interaction with teachers and tutors.&lt;/span&gt;&lt;/p&gt;

The effects of auditory frequency selectivity and phase response on masking were studied using harmonic tone complex maskers with a 100-Hz fundamental frequency. Positive and negative Schroeder-phase complexes (m+ and m-), were used as maskers and the signal was a long-duration sinusoid. In the first experiment, thresholds for signal frequencies of 1 and 4 kHz were measured as a function of masker bandwidth and number of components. A large difference in thresholds between the m+ and m- complexes was found only when masker components were presented ipsilateral to the signal over a frequency range wider than the traditional critical band, regardless of the absolute number of components. In the second experiment, frequency selectivity was measured in harmonic tone complexes with fixed or random phases as well as in noise, using a variant of the notched-noise method with a fixed masker level. The data showed that frequency selectivity is not affected by masker type, indicating that the wide listening bandwidth suggested by the first experiment cannot be ascribed to broader effective filters in complex-tone maskers than in noise maskers. The third experiment employed a novel method of measuring frequency selectivity, which has the advantage that the overall level at the input and the output of the auditory filter remains roughly constant across all conditions. The auditory filter bandwidth measured using this method was wider than that measured in the second experiment, but may still be an underestimate, due to the effects of off-frequency listening. The data were modeled using a single-channel model with various initial filters. The main findings from the simulations were: (1) the magnitude response of the Gammatone filter is too narrow to account for the phase effects observed in the data; (2) none of the other filters currently used in auditory models can account for both frequency selectivity and phase effects in masking; (3) the Gammachirp filter can be made to provide a good account of the data by altering its phase response. The final conclusion suggests that masker phase effects can be accounted for with a single-channel model, while still remaining consistent with measures of frequency selectivity: effects that appear to involve broadband processing do not necessarily require across-channel mechanisms.

Background: Regarding the strong auditory spatial plasticity capability of the central auditory system and the effect of short-term and long-term rehabilitation programs in elderly people, it seems that an auditory spatial training can help this population in informational masking release and better track speech in noisy environments. The main purposes of this study are developing an informational masking measurement test and an auditory spatial training program. Protocol: This study will be conducted in two parts. Part 1: develop and determine the validity of an informational masking measurement test by recruiting two groups of young (n=50) and old (n=50) participants with normal hearing who have no difficulty in understanding speech in noisy environments. Part 2 (clinical trial): two groups of 60-75-year-olds with normal hearing, who complain about difficulty in speech perception in noisy environments, will participate as control and intervention groups to examine the effect of auditory spatial training. Intervention: 8 sessions of auditory spatial training. The informational masking measurement test and Speech, Spatial and Qualities of Hearing Scale will be compared before intervention, immediately after intervention, and one month after intervention between the two groups. Discussion: Since auditory training programs do not deal with informational masking release, an auditory spatial training will be designed, aiming to improve hearing in noisy environments for elderly populations. Trial registration: Iranian Registry of Clinical Trials (IRCT20190118042404N1) on 25th February 2019.

Persons with sensorineural hearing loss experience difficulty in speech perception in noisy environments. They can benefit from signal processing for suppressing the background noise in their hearing aids. For such an application, a speech enhancement technique using spectral subtraction and noise spectrum estimation based on dynamic quantile tracking is presented. It does not involve voice activity detection or storage and sorting of past spectral samples. Enhancement of speech corrupted with different types of additive stationary and non-stationary noise showed improvement in speech quality to be equivalent to an SNR advantage of 3 – 6 dB. The technique is implemented and tested for satisfactory real-time operation, with sampling frequency of 10 kHz, on a 16-bit fixed-point DSP processor with on-chip FFT hardware.

BackgroundHearing loss is the third most prevalent chronic condition faced by older adults and has been linked to difficulties in speech perception, activities of daily living, and social interaction. Recent studies have suggested a correlation between severity of hearing loss and an individual’s cognitive function; however, a causative link has yet to be established. One intervention option for management of the most severe to profound hearing loss in older adults is cochlear implantation. We performed a review to determine the status of the literature on the potential influence of cochlear implantation on cognition in the older adult population.MethodsOver 3800 articles related to cochlear implants, cognition, and older adults were reviewed. Inclusion criteria were as follows: (1) study population including adults > 65 years, (2) intervention with cochlear implantation, and (3) cognition as the primary outcome measure of implantation.ResultsOut of 3,886 studies selected, 3 met inclusion criteria for the review.ConclusionsWhile many publications have shown that cochlear implants improve speech perception, social functioning, and overall quality of life, we found no studies in the English literature that have prospectively evaluated changes in cognitive function after implantation with modern cochlear implants in older adults. The state of the current literature reveals a need for further clinical research on the impact of cochlear implantation on cognition in older adults.

Many hearing-impaired listeners appear to have poor auditory frequency selectivity. However, the data are confounded by the fact that these listeners are usually tested at high SPLs. There is evidence that even in normal listeners frequency selectivity is diminished at high SPLs, though there is some question about the size of this level effect. In two different experiments directed at this issue, we found the decrease in normal selectivity at high SPLs to be small and highly subject dependent. In the first, psychophysical tuning curves were obtained from six listeners at probe levels 40 dB apart. The probe was set at 10 dB SL; the low-level condition was run in quiet, and the high-level condition in a background of intense wide-band noise. The average tuning curve from the high-level condition was a little wider, but one listener actually produced a narrower curve in this condition. In the second experiment we measured the threshold of a tone masked by noise with a cosinusoidal power spectrum. Threshold was first measured with the tonal probe at a spectral peak, and then with the probe in a valley. The difference between the two thresholds, our measure of frequency selectivity, was about 2 dB less at high probe levels than at low probe levels, suggesting only a slight reduction in frequency selectivity at high levels. These results support our view that the deficit in selectivity exhibited by hearing-impaired listeners is not an artifact due to stimulus level. [Work supported by NIH Grant No. NS12045.]