Comparison of McGurk Effect across Three Consonant-Vowel Combinations in Kannada

Dhatri S Devaraju,Ajith Kumar Uppunda,Santosh Maruthy 대한청각학회 2019 Journal of Audiology & Otology Vol.23 No.1

Background and Objectives: The influence of visual stimulus on the auditory component inthe perception of auditory-visual (AV) consonant-vowel syllables has been demonstrated in differentlanguages. Inherent properties of unimodal stimuli are known to modulate AV integration. The present study investigated how the amount of McGurk effect (an outcome of AV integration)varies across three different consonant combinations in Kannada language. Theimportance of unimodal syllable identification on the amount of McGurk effect was also seen. Subjects and Methods: Twenty-eight individuals performed an AV identification task with ba/ga, pa/ka and ma/n· a consonant combinations in AV congruent, AV incongruent (McGurkcombination), audio alone and visual alone condition. Cluster analysis was performed usingthe identification scores for the incongruent stimuli, to classify the individuals into two groups;one with high and the other with low McGurk scores. The differences in the audio alone andvisual alone scores between these groups were compared. Results: The results showed significantlyhigher McGurk scores for ma/n· a compared to ba/ga and pa/ka combinations inboth high and low McGurk score groups. No significant difference was noted between ba/gaand pa/ka combinations in either group. Identification of /n· a/ presented in the visual alonecondition correlated negatively with the higher McGurk scores. Conclusions: The results suggestthat the final percept following the AV integration is not exclusively explained by the unimodalidentification of the syllables. But there are other factors which may also contribute tomaking inferences about the final percept.

Effects of Spatial Training Paradigms on Auditory Spatial Refinement in Normal-Hearing Listeners: A Comparative Study

Nisha Kavassery Venkateswaran,Kumar Ajith Uppunda 대한청각학회 2022 Journal of Audiology & Otology Vol.26 No.3

Background and Objectives: This study compared the effectiveness of two spatial training programs using real and virtual sound sources in refining spatial acuity skills in listeners with normal hearing.Subjects and Methods: The study was conducted on two groups of 10 participants each; groups I and II underwent spatial training using real and virtual sound sources, respectively. The study was conducted in three phases: pre-training, training, and post-training phases. At the pre- and post-training phases, the spatial acuity of the participants was measured using real sound sources through the localization test, and virtual sound sources through the virtual acoustic space identification (VASI) test. The thresholds of interaural time difference (ITD) and interaural level difference (ILD) were also measured. In the training phase, Group I participants underwent localization training using loudspeakers in free field, while participants in Group II were subjected to virtual acoustic space (VAS) training using virtual sound sources from headphones. Both the training methods consisted of 5-8 sessions (20 min each) of systematically presented stimuli graded according to duration and back attenuation (for real source training) or number of VAS locations (for virtual source training).Results: Results of independent t-scores comparing the spatial learning scores (pre vs. post-training) for each measure showed differences in performance between the two groups. Group II performed better than Group I on the VASI test, while the Group I out-performed Group II on the ITD. Both groups improved equally on the localization test and ILD.Conclusions: Based on the present findings, we recommend the use of VAS training as it has practical implications due to its cost effectiveness, need for minimal equipment, and end user usefulness.

Musician-Advantage on Listening Effort for Speech in Noise Perception: A Dual-Task Paradigm Measure

Lavanya Vallampati,Rajaram Ramaprasad,Vaidyanath Ramya,Uppunda Ajith Kumar 대한청각학회 2023 Journal of Audiology & Otology Vol.27 No.4

Background and Objectives: Speech in noise (SIN) perception is essential for effective day-to-day communication, as everyday conversations seldom transpire in silent environments. Numerous studies have documented how musical training can aid in SIN discrimination through various neural-pathways, such as experience-dependent plasticity and overlapping processes between music and speech perception. However, empirical evidence regarding the impact of musical training on SIN perception remains inconclusive. This study aimed to investigate whether musicians trained in South Indian classical “Carnatic” style of music exhibited a distinct advantage over their non-musician counterparts in SIN perception. The study also attempted to explore whether the listening effort (LE) associated in this process was different across musicians and non-musicians, an area that has received limited attention.Subjects and Methods: A quasi-experimental design was employed, involving two groups comprising 25 musicians and 35 non-musicians, aged 18-35 years, with normal hearing. In phase 1, participants’ musical abilities were assessed using the Mini-Profile of Music Perception Skills (Mini-PROMS). In phase 2, SIN abilities were tested using the Tamil phonemically balanced words and Tamil Matrix Sentence Test at -5 dB, 0 dB, and +5 dB SNR. Phase 3 tested LE using a dual-task paradigm including auditory and visual stimuli as primary and secondary tasks.Results: Fractional logit and linear regression models demonstrated that musicians outperformed non-musicians in the Mini-PROMS assessment. Musicians also fared better than non-musicians in SIN and LE at 0 dB SNR for words and +5 dB SNR for sentences.Conclusions: The findings of this study provided limited evidence to support the claim that musical training improves speech perception in noisy environments or reduces the associated listening effort.

모국어 말소리 대조 시 작업기억과 변별능력 간의 연관성

Usha Shastri,Keerthana Kulath Purath Raj,Mable Mathew,Mohan Kumar Kalaiah,Ajith Kumar Uppunda c 한국언어청각임상학회 2019 Communication Sciences and Disorders Vol.24 No.1

배경 및 목적: 모국어의 말소리(phone)를 변별할 때, 특히 도전적 상황에서 이를 수행할 때에는 매우 큰 개인차가 존재한다. 말소리 변별 시 유용한 단서를 활용할 수 있는 능력이 인지능력에 의해 촉진되는지, 이를 통해 개인차를 어느 정도 설명해 줄 수 있는지에 대해서는 잘 알려져 있지 않다. 본 연구는 말라얄람어(Malayalam)를 모국어로 사용하는 청자가 말라얄람어 말소리를 맥락 단서 없이 구분할때 작업기억능력과 변별능력 간에 어떤 연관성이 있는지 알아보고자 하였다. 방법: 말라얄람어를 모국어로 사용하는 18-25세 청자 40 명이 본 연구에 참여하였다. 참여자들로 하여금 무의미단어 사이에 삽입된 말라얄람어 8개 말소리를 변별하도록 하였다. 읽기폭 과제, 조작폭 과제, 숫자 바로외우기 과제, 숫자 거꾸로외우기 과제 등을 이용하여 작업기억능력을 측정하였고, 각 말소리의 변별점수, 전체 말소리 변별점수(8개 말소리로부터 얻은 평균변별점수)와 변별 시 반응시간을 함께 측정하였다. 결과: 참여자의 말소리 변별점수는 57.8%-99%의 범위를 보였다. 피어슨 적률상관분석 결과 모든 작업기억능력 측정치와 전체 말소리 변별점수 간에는 유의한 정적 상관이 나타나 작업기억능력이 말소리 변별에 중요한 역할을 하는 것으로 나타났다. 작업기억능력의 측정치는 말소리 변별점수 다양성의 24.7%를 설명할 수 있었다. 논의 및 결론: 맥락 단서가 없는 상황에서의 말소리 변별은 인지 부담을 높인다. 그러므로 높은 능력은 어려운 상황에서 모국어 말소리를 변별하는 데 도움을 준다. 이 연구는 모국어 말소리 지각에서 인지가 미치는 하향식 영향력을 제시하고 있다. Objectives: Large individual variability is documented for identification performance of native phones, especially in challenging situations. It is not known whether the ability to utilize cues available for phone identification is facilitated by cognitive abilities, thereby explaining a proportion of the individual variability. This study investigated the relationship between working memory capacity and identification of a few Malayalam phones in the absence of contextual cues among native listeners. Methods: Forty native listeners of Malayalam, aged between 18 and 25, participated in this study. Participants identified 8 Malayalam phones embedded in nonsense words. Working memory capacity was measured using tasks such as reading span, operation span, digit forward span, and digit backward span. Identification score for each phone, total phone identification score (average identification score from 8 phones), and reaction time during identification were obtained. Results: Phone identification score of participants ranged from 57.8% to 99%. Pearson product moment correlation analysis showed a significant positive correlation between all measures of working memory capacity and total phone identification score, indicating that working memory capacity play a role in the identification of phones. Reaction time showed a significant negative correlation with digit backward span and operation span. The measures of working memory capacity accounted for 24.7% of the variability in phone identification score. Conclusion: Identification of phones in the absence of contextual cues increases the cognitive load. Therefore, higher working memory capacity might aid in native phone identification in difficult situations. This study reveals the top down influence of cognition on native speech perception.