Speech Recognition Performance of Adults: A Proposal for a Battery for Telugu

Speech audiometry is an essential component of the audiological test battery, as it provides information concerning one’s sensitivity to speech stimuli and the understanding of speech at supra-threshold levels. With regard to the history of materials for speech audiometry, different kinds of materials have been developed by several investigators in English and non-English languages. Several such attempts have also been made to develop and standardize materials for speech audiometry in Indian languages. With reference to Telugu (South Indian Dravidian Language) no such material is available for measuring open-set speech recognition score in adults. Telugu is mother tongue of the majority of people of Andhra Pradesh (Southern State of India) which is divided into three regions. Although, the mother tongue of majority of people of Andhra Pradesh is Telugu, some of the most familiar and frequently used words in one region may not be familiar to people belonging to other regions due to dialectal variations. The purpose of this study is to develop speech material in Telugu which can be commonly used to assess speech recognition performance of individuals belonging to three regions. Four lists of bisyllabic words in Telugu were developed and equivalence analysis of difficulty between the word lists was evaluated for three groups (from three regions) of subjects (age range of 18-25 years) with normal hearing. Subsequently, performance intensity (PI) function for each list was also measured for the three groups. The results revealed that there was no significant difference (p<0.05) between scores obtained by three groups for each list and between four lists for each group. The four word lists developed were found to be equally difficult for all the groups. The performance-intensity (PI) function curve showed semi linear function, and the linear portion of the curve indicated an average linear slope showing 4.64%, 4.62%, 4.52% and 4.54% increase in word recognition score per dB for list 1, list 2, list 3 and list 4 respectively and were found be in accordance with the findings of earlier studies. The four lists thus developed were found to have sufficient reliability and validity in assessing speech recognition performance.