Interaction of hearing impairment, language, and talker on speech recognition

Hearing impairment and age affect speech recognition particularly in acoustically challenging conditions. Studies related to better understanding and improvement of speech recognition in diverse acoustic conditions in different languages /for different talkers considering listeners with different hearing status will be a leitmotiv of this talk.
In order to better understand the underlying mechanisms of speech intelligibility accurate internationally comparable tools are needed. With this aim the Matrix sentence test has been developed in about 20 languages. Although the methodology of the test development was controlled across languages, differences in speech recognitions thresholds in noise of up to 5 dB are noticed for normative data of matrix tests across languages. The first part of the talk will focus on studies investigating the impact of language and talker on speech intelligibility in noise and will ask for acoustic-phonetic cues that might be suitable to predict those differences. Cross-language and –talker comparisons will be shown for German, Spanish, Russian and American English.

The second part of the talk will consider multicenter and multilingual studies with hearing-impaired listeners in order to test the reliability, sensitivity, and specificity of the matrix test for diagnostic purposes. Measurements with hundreds of participants conducted in different countries including Germany, Russia, Italy, Poland, USA or China will be shown. Furthermore, influence of hearing impairment on speech intelligibility in different masking conditions varying from very well controlled laboratory conditions with stationary noise to realistic noise like cafeteria noise will be demonstrated. Here, differentiation of listeners with various degree of hearing impairment using different maskers will be discussed.

Finally, the application of matrix tests and comparisons to existing standard audiometric tools will be shown in terms of hearing rehabilitation with hearing devices like hearing aids and cochlear implants.