Groups Of Listeners Research Articles

The Effects of Signal to Noise Ratio, T60 , Wide-Dynamic Range Compression Speed, and Digital Noise Reduction in a Virtual Restaurant Setting.

Hearing aid processing in realistic listening environments is difficult to study effectively. Often the environment is unpredictable or unknown, such as in wearable aid trials with subjective report by the wearer. Some laboratory experiments create listening environments to exert tight experimental control, but those environments are often limited by physical space, a small number of sound sources, or room absorptive properties. Simulation techniques bridge this gap by providing greater experimental control over listening environments, effectively bringing aspects of the real-world into the laboratory. This project used simulation to study the effects of wide-dynamic range compression (WDRC) and digital noise reduction (DNR) on speech intelligibility in a reverberant environment with six spatialized competing talkers. The primary objective of this study was to determine the efficacy of WDRC and DNR in a complex listening environment using virtual auditory space techniques. Participants of greatest interest were listeners with hearing impairment. A group of listeners with clinically normal hearing was included to assess the effects of the simulation absent the complex effects of hearing loss. Virtual auditory space techniques were used to simulate a small restaurant listening environment with two different reverberation times (0.8 and 1.8 sec) in a range of signal to noise ratios (SNRs) (-8.5 to 11.5 dB SNR). Six spatialized competing talkers were included to further enhance realism. A hearing aid simulation was used to examine the degree to which speech intelligibility was affected by slow and fast WDRC in conjunction with the presence or absence of DNR. The WDRC and DNR settings were chosen to be reasonable estimates of hearing aids currently available to consumers. A WDRC × DNR × Hearing Status interaction was observed, such that DNR was beneficial for speech intelligibility when combined with fast WDRC speeds, but DNR was detrimental to speech intelligibility when WDRC speeds were slow. The pattern of the WDRC × DNR interaction was observed for both listener groups. Significant main effects of reverberation time and SNR were observed, indicating better performance with lower reverberation times and more positive SNR. DNR reduced low-amplitude noise before WDRC-amplified the low-intensity portions of the signal, negating one potential downside of fast WDRC and leading to an improvement in speech intelligibility in this simulation. These data suggest that, in some real-world environments that include both reverberation and noise, older listeners with hearing impairment may find speech to be more intelligible if DNR is activated when the hearing aid has fast compression time constants. Additional research is needed to determine the appropriate DNR strength and to confirm results in wearable hearing aids and a wider range of listening environments.

Dialect identification, intelligibility ratings, and acceptability ratings of dysarthric speech in two American English dialects

ABSTRACT The current study explored the intelligibility and acceptability ratings of dysarthric speakers with African American English (AAE) and General American English (GAE) dialects by listeners who identify as GAE or AAE speakers, as well as listener ability to identify dialect in dysarthric speech. Eighty-six listeners rated the intelligibility and acceptability of sentences extracted from a passage read by speakers with dysarthria. Samples were used from the Atlanta Motor Speech Disorders Corpus and ratings were collected via self-report. The listeners identified speaker dialect in a forced-choice format. Listeners self-reported their dialect and exposure to AAE. AAE dialect was accurately identified in 63.43% of the the opportunities; GAE dialect was accurately identified in 70.35% of the opportunities. Listeners identifying as AAE speakers rated GAE speech as more acceptable, whereas, listeners identifying as GAE speakers rated AAE speech as more acceptable. Neither group of listeners demonstrated a difference in intelligibility ratings. Exposure to AAE had no effect on intelligibility or acceptability ratings. Listeners can identify dialect (AAE and GAE) with a better than chance degree of accuracy. One’s dialect may have an effect on intelligibility and acceptability ratings. Exposure to a dialect did not affect listener ratings of intelligibility or acceptability.

Relationship Between Hearing Loss and Cognitive Function in Elderly Chinese People: A Study Based on Propensity Score Matching

To explore the relationship between hearing loss and cognitive function in the elderly population through propensity score matching method. We analyzed the data of 7605 participants aged 60 and above who were included in the 2018 China Health and Retirement Longitudinal Study (CHARLS). The non-substitutable 1∶1 nearest neighbor matching method without caliper value was used for propensity score matching and G-computation was used to estimate the average treatment effect (ATE) of hearing loss on all dimensions of cognitive function. Before matching, there were 3626 (47.68%) women, with 1409 (18.53%) of whom suffering from hearing loss and 3031 (39.86%) of whom suffering from cognitive impairment. After matching, 1409 subjects were included in the hearing loss group and 1409, in the normal hearing group, with both groups sharing similar distribution of basic demographic characteristics. The results for the average treatment effect of the population indicated that the cognitive function scores of the hearing loss group were lower than those of the normal hearing group, with the overall cognitive function being 0.593 points lower (95% confidence intervel [CI]: －0.916-－0.257, P<0.001), orientation being 0.183 points lower (95% CI: －0.302-－0.055, P=0.004), immediate memory being 0.150 points lower (95% CI: －0.218-－0.085, P<0.001), and language skills being 0.178 points lower (95% CI: －0.303-－0.058, P=0.006). The prevalence of cognitive impairment of the hearing loss group was 4.2% higher than that of the normal hearing group (95% CI: 0.007-0.077, P=0.020). Hearing loss adversely affects the orientation, memory, and language skills of the elderly population and forms a potential risk factor for cognitive impairment in the elderly population.

Compensation for coarticulation despite a midway speaker change: Reassessing effects and implications.

Accounts of speech perception disagree on how listeners demonstrate perceptual constancy despite considerable variation in the speech signal due to speakers' coarticulation. According to the spectral contrast account, listeners' compensation for coarticulation (CfC) results from listeners perceiving the target-segment frequencies differently depending on the contrastive effects exerted by the preceding sound's frequencies. In this study, we reexamine a notable finding that listeners apparently demonstrate perceptual adjustments to coarticulation even when the identity of the speaker (i.e., the "source") changes midway between speech segments. We evaluated these apparent across-talker CfC effects on the rationale that such adjustments to coarticulation would likely be maladaptive for perceiving speech in multi-talker settings. In addition, we evaluated whether such cross-talker adaptations, if detected, were modulated by prior experience. We did so by manipulating the exposure phase of three groups of listeners by (a) merely exposing them to our stimuli (b) explicitly alerting them to talker change or (c) implicitly alerting them to this change. All groups then completed identical test blocks in which we assessed their CfC patterns in within- and across-talker conditions. Our results uniformly demonstrated that, while all three groups showed robust CfC shifts in the within-talker conditions, no such shifts were detected in the across-talker condition. Our results call into question a speaker-neutral explanation for CfC. Broadly, this demonstrates the need to carefully examine the perceptual demands placed on listeners in constrained experimental tasks and to evaluate whether the accounts that derive from such settings scale up to the demands of real-world listening.

Localization of Low- and High-Frequency Sounds in Cochlear Implant Recipients Using a Contralateral Hearing Aid.

The ability to localize sounds is partly recovered in patients using a cochlear implant (CI) in one ear and a hearing aid (HA) on the contralateral side. Binaural processing seems effective at least to some extent, despite the difference between electric and acoustic stimulation in each ear. To obtain further insights into the mechanisms of binaural hearing in these listeners, localization of low- and high-frequency sounds was tested. The study used a within-subject design, where participants were tasked with localizing sound sources in the horizontal plane. The experiment was conducted in an anechoic chamber, where an array of seven loudspeakers was mounted along the 24 azimuthal angle span from -90° to +90°. Stimuli were applied with different frequencies: broadband noise and high- and low-frequency noise. Ten CI recipients participated in the study. All had an asymmetric hearing loss with a CI in the poorer ear and an HA on the contralateral side. Accuracy of sound localization in terms of angular error and percentage of correct localization scores. The median angular error was 40° in bimodal conditions for both broadband noise and high-frequency noise stimuli. The angular error increased to 47° for low-frequency noise stimuli. In the unilaterally aided condition with an HA, only a median angular error of 78° was observed. Irrespective of the frequency composition of the stimuli, this group of bimodal listeners showed some ability to localize sounds. Angular errors were larger than those reported in the literature for bilateral CI users or single-sided deaf listeners with a CI. In the unilateral listening condition with HA, only localization of sounds was not possible for most subjects.

Who said it? Native and non-native listeners' source memory for object-speaker associations

Memory for who said what can help native and non-native listeners identify critical information for use in conversations. In two experiments, source memory for object-speaker associations was tested for listeners varying in language proficiency. Native and non-native participants of English first heard speakers name objects with prototypical color (e.g., broccoli) before they had to indicate who had previously named each object. Speakers either consistently named objects of one color, or they randomly named objects of different colors. While both listener groups associated objects with speakers successfully, in Experiment 1, with black and white images, native listeners showed an advantage in source memory in the color consistent condition over the random condition, while non-native listeners had no such advantage. The finding for non-native listeners was replicated in Experiment 2 with color images. The results confirm the role of source memory representations in communication, but also suggest that encoding object-speaker association in L2 may be less sensitive to consistent patterns in the input.

The influence of listener experience, measurement scale and speech task on the reliability of auditory-perceptual evaluation of vocal quality.

To assess the influence of the listener experience, measurement scales and the type of speech task on the auditory-perceptual evaluation of the overall severity (OS) of voice deviation and the predominant type of voice (rough, breathy or strain). 22 listeners, divided into four groups participated in the study: speech-language pathologist specialized in voice (SLP-V), SLP non specialized in voice (SLP-NV), graduate students with auditory-perceptual analysis training (GS-T), and graduate students without auditory-perceptual analysis training (GS-U). The subjects rated the OS of voice deviation and the predominant type of voice of 44 voices by visual analog scale (VAS) and the numerical scale (score "G" from GRBAS), corresponding to six speech tasks such as sustained vowel /a/ and /ɛ/, sentences, number counting, running speech, and all five previous tasks together. Sentences obtained the best interrater reliability in each group, using both VAS and GRBAS. SLP-NV group demonstrated the best interrater reliability in OS judgment in different speech tasks using VAS or GRBAS. Sustained vowel (/a/ and /ɛ/) and running speech obtained the best interrater reliability among the groups of listeners in judging the predominant vocal quality. GS-T group got the best result of interrater reliability in judging the predominant vocal quality. The time of experience in the auditory-perceptual judgment of the voice, the type of training to which they were submitted, and the type of speech task influence the reliability of the auditory-perceptual evaluation of vocal quality.

Assessing Speech Audibility via Syllabic-Rate Neural Responses in Adults and Children With and Without Hearing Loss.

An objective method for assessing speech audibility is essential to evaluate hearing aid benefit in children who are unable to participate in hearing tests. With consonant-vowel syllables, brainstem-dominant responses elicited at the voice fundamental frequency have proven successful for assessing audibility. This study aimed to harness the neural activity elicited by the slow envelope of the same repetitive consonant-vowel syllables to assess audibility. In adults and children with normal hearing and children with hearing loss wearing hearing aids, neural activity elicited by the stimulus /su∫i/ or /sa∫i/ presented at 55-75 dB SPL was analyzed using the temporal response function approach. No-stimulus runs or very low stimulus level (15 dB SPL) were used to simulate inaudible conditions in adults and children with normal hearing. Both groups of children demonstrated higher response amplitudes relative to adults. Detectability (sensitivity; true positive rate) ranged between 80.1 and 100%, and did not vary by group or stimulus level but varied by stimulus, with /sa∫i/ achieving 100% detectability at 65 dB SPL. The average minimum time needed to detect a response ranged between 3.7 and 6.4 min across stimuli and listener groups, with the shortest times recorded for stimulus /sa∫i/ and in children with hearing loss. Specificity was >94.9%. Responses to the slow envelope of non-meaningful consonant-vowel syllables can be used to ascertain audible vs. inaudible speech with sufficient accuracy within clinically feasible test times. Such responses can increase the clinical usefulness of existing objective approaches to evaluate hearing aid benefit.

Effect of Hearing Status on Concussion Knowledge and Attitudes of Collegiate Athletes.

Collegiate athletes who are deaf or hard-of-hearing (D/HoH) are diagnosed with concussions at a similar rate as athletes who are hearing; however, little evidence exists on knowledge and attitudes of athletes who are D/HoH toward concussions. This study aimed to examine differences in knowledge of and attitudes toward concussions between athletes who are D/HoH and athletes who are hearing. Cross-sectional research design. Of the 310 athletes who are D/HoH and 430 athletes who are hearing that were invited to participate, 90 athletes who are D/HoH, and 72 athletes who are hearing completed the survey. The Rosenbaum Concussion Knowledge and Attitudes Survey was used to quantify knowledge of and attitude toward concussions. The Rosenbaum Concussion Knowledge and Attitudes Survey consists of the concussion knowledge index (CKI) and the concussion attitudes index (CAI) subscales. Linear regressions were run to test the association of hearing status with CKI and CAI scores. Pearson correlations were performed to determine relationships between CKI and CAI for athletes who are D/HoH and athletes who are hearing. Alpha level was set a priori at P ≤ .05. Athletes who are hearing demonstrated a higher CKI component score (19.58 [2.19]) compared to athletes who are D/HoH (16.14 [3.31]; P < .001). There were no statistical differences in CAI between hearing groups (hearing: 57.18 [8.73], D/HoH: 55.97 [9.92]; P = .41). There was a moderate positive correlation between CKI and CAI (r = .58) for athletes who are D/HoH, while a weak positive correlation (r = .30) for athletes who are hearing was observed. Athletes who are D/HoH have poorer knowledge of concussions but similar attitudes toward concussion as that of athletes who are hearing. Current concussion educational interventions are in written or spoken form which may not be inclusive to athletes who are D/HoH. Health care professionals should consider an athlete's preferred communication mode to improve the efficiency and effectiveness of education.

Preservation of Residual Hearing: Long-Term Results With a Mid-Scala Electrode.

The long-term preservation of residual hearing after cochlear implantation has become a major goal over the past few years. The aim of the present study was to evaluate residual hearing in the long-term follow-up using mid-scala electrodes. In this retrospective, single-center study, we collected data from 27 patients who were implanted between 2014 and 2015 with residual hearing in the low-frequency range using a mid-scala electrode. Measurements of the hearing thresholds were carried out directly postoperatively (day 1 after surgery) and in the long-term follow-up 43.7 ± 6.9 months. The calculation of the extent of audiological hearing preservation was determined using the HEARRING group formula by Skarsynski. Postoperative preservation of residual hearing was achieved in 69.2% of the cases in the low-frequency range between 250 Hz and 1 kHz, of which 89.5% of the patients had frequencies that suggested using electroacoustic stimulation (EAS). In the long-term follow-up, 30.8% of the patients showed residual hearing; however, 57.1% had apparently benefited from EAS. Preservation of residual hearing is feasible in the long term using mid-scala electrodes. Postoperatively, there is over the half of patients who benefit from an EAS strategy. The long-term follow-up shows a certain decrease in residual hearing. However, these results are comparable to studies relating to other types of electrodes. Further research should be conducted in future to better evaluate hearing loss in long-term follow-up, compared to direct postoperative audiological results.

Evaluating Listening Effort in Unilateral, Bimodal, and Bilateral Cochlear Implant Users.

Evaluate listening effort (LE) in unilateral, bilateral, and bimodal cochlear implant (CI) users. Establish an easy-to-implement task of LE that could be useful for clinical decision making. Prospective cohort study. Tertiary neurotology center. The Sentence Final Word Identification and Recall Task, an established measure of LE, was modified to include challenging listening conditions (multitalker babble, gender, and emotional variation; test), in addition to single-talker sentences (control). Participants listened to lists of sentences in each condition and recalled the last word of each sentence. LE was quantified by percentage of words correctly recalled and was compared across conditions, across CI groups, and within subjects (best aided vsmonaural). A total of 24 adults between the ages of 37 and 82 years enrolled, including 4 unilateral CI users (CI), 10 bilateral CI users (CICI), and 10 bimodal CI users (CIHA). Task condition impacted LE (P < .001), but hearing configuration and listener group did not (P = .90). Working memory capacity and contralateral hearing contributed to individual performance. This study adds to the growing body of literature on LE in challenging listening conditions for CI users and demonstrates feasibility of a simple behavioral task that could be implemented clinically to assess LE. This study also highlights the potential benefits of bimodal hearing and individual hearing and cognitive factors in understanding individual differences in performance, which will be evaluated through further research.

KONSEP INCEP DALAM PENYAJIAN KOTEKAN GAMELAN GONG KEBYAR

Balinese gamelan music has its own aesthetic dimensions for the &#x0D; group of performers and listeners. However, it can be realized that &#x0D; achieving a beautiful aesthetic dish is not an easy matter. Especially &#x0D; for those who are new to, studying, or who do not own cultural &#x0D; products. This research tries to investigate further the concept of &#x0D; incep which is one of the references for the aesthetic value of &#x0D; Balinese gamelan offerings, especially Gong Kebyar. The aim is to &#x0D; find components that form concepts that can be used as guidelines&#x0D; in the art inheritance system and its performances. The author uses&#x0D; a qualitative research model, with a textual ethnomusicological &#x0D; approach and the working theory popularized by Rahayu &#x0D; Supanggah. Based on the research carried out, it can be seen that &#x0D; the concept of incep is related to the value of a dish which includes &#x0D; instrument blows that sound clear, precise and compact. The&#x0D; components that form the concept consist of ngatih, celang, and &#x0D; maketekan. These three components have sub-requisites to achieve &#x0D; the desired value. Because if it cannot be fulfilled then it is certain &#x0D; that there will be sounds that are less clean or uncomfortable to hear &#x0D; in the ear. On the other hand, if everything can be fulfilled, then &#x0D; surely the percussion performance can achieve the aesthetic value &#x0D; of the incep performance

Voice disguise and foreign accent: Prosodic aspects of English produced by Bra-zilian Portuguese speakers

This study aims to explore how much a speaker of English as a foreign language can mask one’s accent by performing voice disguise toward a native-like accent, and what implications it might bring forward. For the Methods, we conducted three experiments, (a) both the native and the foreign groups produced authentic voices, (b) the native group performed authentic voice and the foreign group performed disguised voice, and (c) a group of native listeners of English rated the degree of foreign accent from experiments a and b. The results showed evidence of correlation between the ratings and authentic voices. Nevertheless, they remained somewhat inconclusive for the disguised voice. It may be concluded that the more the Brazilian speaker approaches the L1-English target accent when voice disguising, the harder it is for the listener to recognize his/her L2-English accent.

“In Women’s Hands”

Eugenics had popular appeal and expressions in early 20th-century Denmark. This article tells two stories of what eugenics looked like ‘in the hands’ of bourgeois Danish women as they promoted ‘racial hygiene’ through cultural production. The first story highlights the eugenic feminism of nationally acclaimed women’s rights advocate Thit Jensen through a reading of her play The Stork (1929). The second tells of the Copenhagen Housewife Association’s engagement with new media technology and race science through their eugenics radio Listener Group (1934). Read through a lens that pays especially close attention to race and class, I argue that this work identifies them as significant proponents of eugenic ideology and as contributors to the targeting of the poor and working class in the name of ‘racial hygiene’ – a decidedly racist project.

Recognition of Speech With Dynamic Pitch Manipulation in Noise: Effects of Manipulation Methods.

Dynamic pitch, which is defined as the variation in fundamental frequency in speech, is one of the acoustic cues that affect speech recognition in noise. Built on the evidence that a symmetrical manipulation of dynamic pitch led to poorer speech recognition, the present study examined the effect of an asymmetrical manipulation method on speech recognition in noise by younger and older adults. Speech recognition accuracy in noise was measured from younger adults with normal hearing in Experiment 1, and speech reception threshold (in dB SNR) from older adults with normal hearing to mild-moderate hearing loss in Experiment 2. The dynamic pitch contours of the speech stimuli were manipulated using both symmetrical and asymmetrical methods. Younger adults recognized speech better in noise with asymmetrical than symmetrical manipulation, and with weakened than strengthened dynamic pitch. A substantial amount of variability was observed in a group of older listeners. This variability was predominately predicted by the listeners' age but not hearing thresholds or their ability to perceive dynamic pitch in fluctuating noise. The asymmetrical manipulation of dynamic pitch had a less negative effect than the symmetrical manipulation. This effect also interacted with pitch-change direction. These findings suggest the influence of perceptual naturalness on speech recognition with signal modification. Directions for future research are also discussed.

Representation of Voice Hearing Groups by French Mental Health Professionals.

Hearing voices groups (HVGs) are an alternative way of treating acoustic-verbal hallucinations. Although they have been developing in France for the last decade, they have lagged behind their international expansion. The representations that circulate about their functioning and their effects are likely to influence the referral to these groups by mental health professionals. We created and used a questionnaire to survey mental health professionals' representations of voice hearing groups. We surveyed 79 French health professionals using a questionnaire with 19 closed items. 7 additional items allowed us to specify the professional status and familiarity of the participants with the HVGs. Professionals generally shared positive representations of HVGs but had very approximate knowledge of them. The subgroup of the most familiar professionals (N = 45) differed significantly on 7 items from the subgroup of non-familiars (N = 35). HVGs are represented as one medical offer among others, of little clinical use and indicated only for psychotic voice-hearing patients, which seems to be a misunderstanding in every case. However, our study also shows that these opinions evolve with the degree of familiarity with HVGs. Certain representations need to be corrected so that quality information can be circulated about HVGs and improve their integration into their ecosystem.

Neuroplastic changes in functional wiring in sensory cortices of the congenitally deaf: A network analysis.

Congenital sensory deprivation induces significant changes in the structural and functional organisation of the brain. These are well-characterised by cross-modal plasticity, in which deprived cortical areas are recruited to process information from non-affected sensory modalities, as well as by other neuroplastic alterations within regions dedicated to the remaining senses. Here, we analysed visual and auditory networks of congenitally deaf and hearing individuals during different visual tasks to assess changes in network community structure and connectivity patterns due to congenital deafness. In the hearing group, the nodes are clearly divided into three communities (visual, auditory and subcortical), whereas in the deaf group a fourth community consisting mainly of bilateral superior temporal sulcus and temporo-insular regions is present. Perhaps more importantly, the right lateral geniculate body, as well as bilateral thalamus and pulvinar joined the auditory community of the deaf. Moreover, there is stronger connectivity between bilateral thalamic and pulvinar and auditory areas in the deaf group, when compared to the hearing group. No differences were found in the number of connections of these nodes to visual areas. Our findings reveal substantial neuroplastic changes occurring within the auditory and visual networks caused by deafness, emphasising the dynamic nature of the sensory systems in response to congenital deafness. Specifically, these results indicate that in the deaf but not the hearing group, subcortical thalamic nuclei are highly connected to auditory areas during processing of visual information, suggesting that these relay areas may be responsible for rerouting visual information to the auditory cortex under congenital deafness.

Tinnitus Relief Effect According to the Stimulus Listening Method of Sound Therapy

Purpose: This study investigated the tinnitus relief effect of the stimulation listening method in sound therapy. Methods: The participants were randomly divided into two groups: 16 in the continuous listening group and 15 in the intermittent listening group. The participants listened to broad-band noise at the mixing point level for 3 months, either continuously for 2 hours or intermittently 4 hours for 30 minutes, depending on the group allocation. The results of this study were confirmed by measuring scores through the Korean version of the Tinnitus Primary Function Questionnaire (K-TPFQ) and visual analog scale (VAS) for tinnitus loudness and annoyance at pretreatment and at 1, 2, and 3 months follow-ups. Results: Average scores of the K-TPFQ and VAS for tinnitus loudness and annoyance significantly improved with the duration of sound therapy in both the continuous listening and intermittent listening groups (&lt;i&gt;p&lt;/i&gt; &lt; 0.05). However, there was no difference between the two groups regarding the stimulation listening method in sound therapy, and no significant interaction effects were confirmed. Conclusion: The method of listening to the sound therapy continuously for 2 hours and the method of listening intermittently for 30 minutes had similar tinnitus relief effects.

Genotypic and Allelic Frequencies of GJB2 Variants and Features of Hearing Phenotypes in the Chinese Population of the Dongfeng-Tongji Cohort.

This study aimed to describe the distribution of the genotype and allele frequencies of GJB2 variants in the Chinese population of the Dongfeng Tongji cohort and to analyze the features of the hearing phenotype. We used data from 9910 participants in the Dongfeng Tongji cohort in 2013 and selected nine GJB2 variants. Pure tone audiometry was employed to measure hearing. Differences in genotype and allele frequencies were analyzed via chi-squared test or Fisher's exact test. Of the 9910 participants, 5742 had hearing loss. The genotype frequency of the GJB2 variant c.109G>A was statistically significantly distributed between the normal and impaired hearing groups, but not for the variant c.235delC. A higher frequency of the c.109G>A homozygous genotype was found in the hearing loss group (0.5%) than in the normal hearing group (0.1%). Patients with c.109G>A and c.235delC homozygous mutations exhibited varying degrees of hearing loss, mainly presenting sloping and flat audiogram shapes. A significant difference was found in the genotype frequency of the GJB2 variant c.109G>A between the case and control groups, but not in that of the variant c.235delC. Different degrees of hearing loss and various audiogram shapes were observed in patients with c.109G>A and c.235delC homozygous mutations.

Revisiting frequencies of phonological sound classes in speech input: Change over time in child-directed speech.

The purpose of the current study was to revisit a controversial topic: whether frequencies of phonological consonant and vowel classes differ in speech directed to children and to adults. In addition, the current study investigated whether the frequency of phonological consonant and vowel classes changes with children's increasing chronological and/or developmental age. This study analyzed speech input from 44 adults to four different age groups of listeners (i.e., three groups of children at 6, 18, and 36 months of age and one group of adult listeners) in terms of frequency of occurrence of consonant and vowel classes. Results revealed that consonant stop, nasal, fricative and glide manner classes as well as all four consonant place classes were significantly different in speech directed to the four different age groups. A perspective is discussed to better understand the nature of frequency input of phonological sound classes.