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Objective: The present study compared recognition of native and non-native consonants in quiet and noise among native speakers of Malayalam., Methods and Material: Fifteen native speakers of Malayalam who had English as the medium of instruction at school participated in the study. Stimuli comprised of 16 vowel-consonants-vowel nonsense syllables spoken by eight native speakers of Malayalam (native consonants) and eight native speakers of American English (non-native consonants). Recognition of native and non-native consonants was studied in quiet and in the presence of speech-shaped noise at signal-to-noise ratios (SNRs) of 8 dB, 0 dB, and -8 dB. The consonant recognition task was carried out as 16-alternative forced-choice procedure, and the responses were stored as confusion matrix., Results: In favourable listening condition (i.e., quiet and 8 dB SNR), the recognition score for native consonants was greater than non-native consonants. In contrast, at 0 dB SNR and -8 dB SNR, the recognition score of non-native consonants was greater than native consonants. Information transfer analysis revealed that the transfer of information was highest for consonant feature manner of articulation and lowest for voicing, across listening conditions for both native and non-native consonants., Conclusions: Recognition of native and non-native consonants were affected differently in the presence of speech-shaped noise among native speakers of Malayalam. In favourable listening condition, recognition of native consonants was better than non-native consonants. However, in challenging listening condition, non-native consonants were found to be recognised better than native consonants., Competing Interests: None

Purpose: Sensory gating is the cortical phenomenon that involves selective inhibition of responses to task-irrelevant stimuli. Perceiving speech in noise, a situation commonly encountered by humans, requires the irrelevant noise to be inhibited while processing the relevant speech stimulus. We hypothesized that the two (sensory gating and speech perception in noise [SPiN]) might be related and that sensory gating may provide evidence of cortical inhibition involved in SPiN. Method: An observational research following a correlational design was conducted on 10 neurotypical individuals. Auditory sensory gating was assessed using a conditioning--testing paradigm for tone and speech token pairs. The SPiN was measured using standardized sentences in the participants' native language. Results: Differences were observed in the gating index of the P2 peaks of speech and tone pairs. A significant relationship between SPiN and the auditory sensory gating of the P2 peak of the speech-evoked cortical potential was obtained. Conclusion: The results of this preliminary investigation indicate an association between the sensory gating mechanism and neurotypical individuals' ability to perceive speech in noise. [ABSTRACT FROM AUTHOR]

Perceptual restoration occurs when the brain restores missing segments from speech under certain conditions. It is investigated in the auditory modality, but minimal evidence has been collected during speechreading tasks. The authors measured perceptual restoration in speechreading by individuals with hearing loss and compared it to perceptual restoration in auditory speech by normally hearing individuals. Visual perceptual restoration for speechreading was measured in 33 individuals with profound hearing loss by blurring the keywords in silent video recordings of a speaker uttering a sentence. Auditory perceptual restoration was measured in 33 normally hearing individuals by distorting the keywords in spoken sentences. It was found that the amount of restoration was similar for speechreading through the visual modality by individuals with hearing loss and speech perception through the auditory modality by normally hearing individuals. These findings may facilitate understanding of speech processing by individuals with hearing loss. [ABSTRACT FROM AUTHOR]

Introduction: We aimed to develop sentence lists in Tulu language to measure speech recognition thresholds (SRTs) in noise and verify the equivalence of the developed lists in noise among individuals with normal hearing. Methods: This cross-sectional study was conducted in three phases; first, the developmental phase, collection, and development of the sentence material in the Tulu language were carried out. Sentences rated highly familiar/familiar and highly natural/natural by 80% of the raters were considered for the next phase. In the second phase, 22 sentence lists were prepared, with each list containing ten sentences of equal difficulty level in noise. The difficulty level was matched mainly based on the similarity (±1 standard deviation [SD]) of signal-to-noise ratio 50 (SNR-50), the slope of the sentences, the number of content words, and phonemes. The third phase evaluated the equivalency of developed sentence lists. Sixty-two native Tulu speakers with normal hearing sensitivity, aged between 18 and 39 years, participated. Of these 62 participants, twelve were recruited for the first phase, 20 individuals participated in the second phase, and 30 participated in the third phase. Results: Thirteen sentence lists were equivalent and were a reliable measure of SNR-50 in native speakers of Tulu who have hearing sensitivity within normal limits. Using the sentence scoring method, the average SNR-50 of these sentence lists was - 4.19 dB with a SD of 0.21 dB. The developed sentences also had less within-subject variability than between-subject variability. Conclusions: These 13 equivalent sentence lists provide a valid and reliable tool to measure the SRT in noise in native Tulu speakers with hearing sensitivity within normal limits. [ABSTRACT FROM AUTHOR]

Purpose: Auditory training is known to improve the speechperception- in-noise (SPIN) skills in children with auditory processing disorders (APDs); however, conventional non-- computer-based trainings are dreary and nonmotivating. This study intended to develop a computer-based noise desensitization training module in Indian English and test the efficacy of the same in children with APD having SPIN deficits. There are no such modules available at present to be used in Indian children. Method: The module incorporated words-in-noise training, with monosyllables and trisyllables as target words in the presence of speech-shaped noise as well as multitalker babble at different signal-to-noise ratios ranging from +20 to -4 dB SNR. The study included 20 children with SPIN deficits diagnosed with APD and who were recruited randomly to the experimental group who received the training (n = 10; Mage = 11.1 years) and to the control group who did not receive any training (n = 10; Mage = 11.4 years). The outcome measures included behavioral measures and electrophysiological measures (auditory long latency responses for speech in quiet and noise). Results: Compared to children in the control group, children in the experimental group exhibited improvements in the SPIN scores as well as temporal processing measures after training. Dichotic consonant--vowel tests and auditory memory and sequencing tests did not yield significant improvement post training. Also, auditory long latency responses in quiet and noise revealed significant reduction in the amplitudes after training. No significant difference was noted in the latencies of auditory long latency responses post training. Control group participants did not show any significant difference in any of the measures between the initial and follow-up evaluations. Conclusions: The developed training module was successful in fetching improvements in behavioral and electrophysiological measures. It would be a great addition to the evidence-based rehabilitation support inventory for children with SPIN deficits in India. [ABSTRACT FROM AUTHOR]

Objective: The human auditory system perceives any speech sound through the inherent temporal cues i.e., the temporal fine structure (TFS) and envelope (ENV) cues which has its own predominance for perception across languages. Research in English and Mandarin Chinese language showed the difference between these cues with tonal language employ more of TFS cues and non-tonal language employ ENV cues for perception. Earlier studies on Indian language (Kannada and Malayalam) revealed ENV cues predominance for perception. Based on this, the aim of this study was to compare stimuli in which the TFS and ENV cues had been interchanged (so-called auditory chimeras). The stimuli were Malayalam language sentences delivered through a hearing aid using two compression schemes -- syllabic compression and dual compression -- and processed by a nonlinear 8-channel and 16-channel system. Method: Thirty-five normal hearing individuals were assessed for the perception of chimeric sentences across eight sets of frequency bands (1, 4, 6, 8, 16, 24, 32, and 64 bands). Before the administration of the chimeric sentences all the individuals were assessed for normal hearing abilities through routine audiological evaluations. Results: The results of the present study reveal there is a significant difference across frequency bands on both the syllabic and dual compression processed stimuli using either 8 or 16 channels. The ENV cues were better perceived whether 4, 6, 8, or 16 frequency bands were used, with dual compression being marginally better than syllabic compression for both 8 and 16 channels. However, 16 channels gave overall better perception than 8 channels. Conclusions: The results of the study revealed a better processing of envelope (ENV) cues, which are most important for understanding speech through a hearing aid. [ABSTRACT FROM AUTHOR]

Purpose: The study aimed to assess the relationship between the level-dependent function of efferent inhibition and speech perception in noise across different intensities of suppressor and across different signal-to-noise ratios (SNRs) of speech. Method: Twenty-six young normal-hearing adults participated in the study. Contralateral suppression of transient evoked otoacoustic emissions (TEOAEs) was measured for 3 levels of suppressor (40, 50, and 60 dB SPL). Speech identification score (SIS) was measured at 5 ipsilateral SNR conditions (quiet, 0, -5, -10, and -15 dB), with and without contralateral broadband noise at 3 levels (40, 50, and 60 dB SPL). Furthermore, SNR-50 was measured with and without the same 3 levels of contralateral broadband noise. Results: The results showed that the suppression magnitude of TEOAE increased with an increase in suppressor level. However, neither SIS nor SNR-50 was influenced by the contralateral noise. In addition, SIS and SNR-50 did not show significant correlation with contralateral suppression of TEOAEs. This was true at all the SNRs and contralateral noise levels used in the study. Conclusions: The findings suggest that the intensity of noise directly influences medial olivocochlear bundle--mediated efferent inhibition. However, the role of the medial olivocochlear bundle in regulating speech perception in noise needs to be revisited. [ABSTRACT FROM AUTHOR]

Background: The Acceptable Noise Level (ANL) is a measure of an individual's ability to tolerate background noise while listening to speech. Based on their ANL scores, people can be categorised into 'low', 'mid', or 'high' ANL groups. However, there are reports of subtle central auditory effects on the variation of ANL in normal hearing subjects. Because these reports are based on various objective test findings and interpretations, process-based central auditory testing and subjective authentication is essential in order to understand central involvement in individuals with various degrees of ANL. Methods: A total of 106 Kannada-speaking adults with normal hearing sensitivity participated in the study. Their ANLs were measured and they were then classified into 'low', 'mid', and 'high' groups. The temporal resolution abilities in these participants were tested using the Gap in Noise (GIN) test. Results: Descriptive analysis along with parametric statistical evaluations were carried out to compare the GIN scores of the three groups. One-way ANOVA revealed that the GIN scores were not statistically different (p>0.05) between the groups. Conclusions: The result suggests that the temporal resolution of individuals with varying degrees of ANLs is comparable. The absence of temporal resolution difficulties in individuals with varying degrees of ANL do not necessarily contradict earlier reports, as they could have other central auditory processing difficulties. More research is required to clarify these difficulties. [ABSTRACT FROM AUTHOR]

Objective: To develop sentence lists in the Telugu language for the assessment of speech recognition threshold (SRT) in the presence of background noise through identification of the mean signal-to-noise ratio required to attain a 50% sentence recognition score (SRTn).Design: This study was conducted in three phases. The first phase involved the selection and recording of Telugu sentences. In the second phase, 20 lists, each consisting of 10 sentences with equal intelligibility, were formulated using a numerical optimisation procedure. In the third phase, the SRTn of the developed lists was estimated using adaptive procedures on individuals with normal hearing.Study sample: A total of 68 native Telugu speakers with normal hearing participated in the study. Of these, 18 (including the speakers) performed on various subjective measures in first phase, 20 performed on sentence/word recognition in noise for second phase and 30 participated in the list equivalency procedures in third phase.Results: In all, 15 lists of comparable difficulty were formulated as test material. The mean SRTn across these lists corresponded to −2.74 (SD = 0.21).Conclusions: The developed sentence lists provided a valid and reliable tool to measure SRTn in Telugu native speakers. [ABSTRACT FROM AUTHOR]

Introduction: Background noise affects the listening environment inside classrooms, especially for younger children. High background noise level adversely affects not only student speech perception but also teacher vocal hygiene. The current study aimed to give an overview of the classroom listening conditions in selected government primary schools in India.Materials and Methods: Noise measurements were taken in 23 classrooms of four government primary schools in southern India, using a type 2 sound level meter. In each classroom measurements were taken in occupied and unoccupied conditions. Teacher voice level was measured in the same classrooms. In addition, the classroom acoustical conditions were observed and the reverberation time for each classroom was calculated.Results: The mean occupied noise level was 62.1 dBA and 65.6 dBC, and the mean unoccupied level was 62.2 dBA and 65 dBC. The mean unamplified teacher speech-to-noise ratio was 10.6 dBA. Both the occupied and unoccupied noise levels exceeded national and international recommended levels and the teacher speech-to-noise ratio was also found to be inadequate in most classrooms. The estimated reverberation time in all classrooms was greater than 2.6 seconds, which is almost double the duration of accepted standards. In addition, observation of classrooms revealed insufficient acoustical treatment to effectively reduce internal and external noise and minimize reverberation.Conclusion: The results of this study point out the need to improve the listening environment for children in government primary schools in India. [ABSTRACT FROM AUTHOR]

Background: This work studied, in individuals with normal hearing, the perception of time-compressed speech, compression ratio, and speech perception in noise using phonemically balanced (PB) word lists in Kannada. The effect of age was also studied. Materials and Methods: Participants were 29 young and middle-aged adults (native Kannada speakers) aged 15 to 50 years. The Speech Perception in Noise (SPIN) test was administered at signal to noise ratios (SNRs) of +5 dB, 0 dB, -5 dB, and in quiet. The Time-Compressed Speech Test (TCST) was administered on all participants at compression ratios of 0%, 40%, 50%, and 60%. Results: Young adults performed better than middle-aged adults in both the TCST and SPIN tests. As difficulty levels rose, performance decreased in both tests. Conclusions: Even in individuals with normal hearing, ageing has a deleterious effect on the performance of the central auditory processing system, which is necessary for speech perception under adverse listening conditions. [ABSTRACT FROM AUTHOR]

The present study aimed to investigate the effect of vowel length and noise on perception of stop-glide continuum. A nine point stop-glide continuum was created by varying the onset frequency of second formant. The continuum was then manipulated for two lengths of vowel following the consonant and three levels of background noise. The stimuli were presented to 30 normal hearing adult participants and the responses were recorded for identification and reaction time task. The results for the identification task revealed that vowel length had a significant effect on the perceptual process with the categorical boundary shifted towards the perception of stop consonant in the presence of long vowel. However, in the presence of noise, the effects of vowel length cues were limited. In such condition, the probable role of multiple acoustic cues in the perception of speech sounds is suggested. On the contrary, no significant effect of vowel length and/or noise was observed in the time taken for the participants to respond to the stimuli. These results were discussed in terms of the role of perceptual normalcy influencing the effect of noise. [ABSTRACT FROM AUTHOR]