Setting Hearing Aids Differently for Different Languages

ABSTRACT

In setting a hearing aid, the Speech Intelligibility Index (SII)—the percentage of speech cues that are audible—tells most of the story but is far from the entire picture. It can provide information on the various frequency importance bands in different languages (and thereby which phonemes or speech sounds are important), but it does not provide information on word-level and sentence-level cues that may be very important as well. Phoneme-level differences (seen in an SII) could result in a change in the frequency response and output specification for hearing aids such as an increase bass response in a language that has a larger number of sonorants than English or an increase in the frequency response in the 3000-Hz region for those (Slavic) languages that have palatalization as a distinctive cue. However, word- and sentence-level differences would not typically be seen in the SII measure and may necessitate changes in various compression-related parameters. For example, languages such as Japanese that have a rigid morphological consonant-vowel-consonant structure may necessitate a different release time for their nonlinear processing to maintain audibility of the quieter consonants. Sentence-level differences seen for subject-object-verb languages such as Hindi and Urdu may require increased amplification for soft-level inputs. Specific recommendations on how to program a hearing aid for many non-English languages are given, based on their phoneme-, word-, and sentence-level grammatical characteristics.

KEYWORDS

Languages - SVO - SOV - WDRC - release time - SII - hearing aids - program

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