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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]

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]

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]

Background: The aim of the study was to investigate whether noise reduction algorithms are beneficial for speech perception in the presence of noise in children using cochlear implants. Further, the study also aimed to determine whether any difference in speech perception existed between different pre-processing strategies such as Adaptive Dynamic Range Optimization (ADRO), Autosensitivity Control (ASC), and the two-stage adaptive beam-forming algorithm (Beam) in different signal-to-noise ratios (SNRs). Material and Method: Speech identification scores of the participants were tested in quiet with the 'Everyday' default setting activated. They were also tested using speech in noise at +5 dB and +10 dB SNR with ADRO, ASC, and Beam activated. Exactly 17 children using Nucleus cochlear implants for at least 1 year were tested. Results: A significant difference was found between performance in quiet (in the 'Everyday' default setting) and in the presence of noise (with ADRO, ASC, and Beam). No significant difference was found between the 3 pre-processing strategies at both SNRs and between the 2 SNRs for all 3 strategies. Conclusions: In conditions where the signal and noise emerge from in front of the listener, no influence of the pre-processing strategies was seen. [ABSTRACT FROM AUTHOR]