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

Abstract

Abstract-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.

Conventional speech identification test in Marathi for adults

“…Several such attempts have also been made to develop and standardize materials for speech audiometry in Indian languages such as Hindi, Tamil, Gujarati, Kannada, Mizo, Rajasthani, Telugu etc. [3][4][5][6][7][8][9] Marathi is a southern Indo-Aryan language and is one of 23 official languages of India. Marathi is the official language of Maharashtra and Goa.…”

“…6 Similarly, Kumar and Mohanty have also faced difficulty in collecting meaningful monosyllabic words for preparing materials for assessing speech recognition performance in Telugu, a South Central Dravidian language with very few monosyllabic words. 9 This could be attributed to the reason that Telugu is another vowel ending language like Italian and Kannada. Hence, Kumar and Mohanty developed word lists by considering disyllabic words having CVCV structure for assessing speech recognition performance.…”

“…Hence, Kumar and Mohanty developed word lists by considering disyllabic words having CVCV structure for assessing speech recognition performance. 9 In view of above, Kumar and Mohanty summarized that speech identification or recognition score testing is a procedure of establishing the percentage of correctly identified or recognized monosyllabic words presented at comfortable supra-threshold level, provided the particular language contains adequate number of meaningful monosyllabic words. 20 However, languages which end in vowels may not contain plenty of meaningful monosyllabic words and hence, disyllabic words can be used for this purpose in such languages.…”

“…9 In view of above, Kumar and Mohanty summarized that speech identification or recognition score testing is a procedure of establishing the percentage of correctly identified or recognized monosyllabic words presented at comfortable supra-threshold level, provided the particular language contains adequate number of meaningful monosyllabic words. 20 However, languages which end in vowels may not contain plenty of meaningful monosyllabic words and hence, disyllabic words can be used for this purpose in such languages. Thus, they concluded that "speech identification or recognition score is the percentage (%) of correctly identified or recognized test words which are minimum meaningful units of a language and presented at comfortable supra-threshold level".…”

“…19 In view of above, Kumar and Mohanty, have also argued that consonantal aspect of phonemic balance is important as the perception of consonants is much more complex than vowel perception due to their low intensity, more susceptible to degradation and varied classifications. 9,20 Hence, they developed word lists in Telugu by considering only the consonantal aspects of phonemic balance. This makes the consonantal aspect of phonemic balance a priority in the development of word lists for assessing speech recognition performance, and hence, we also considered this aspect of phonemic balance is reasonable in the present study.…”