Real-Time Contrast Enhancement to Improve Speech Recognition

An algorithm that operates in real-time to enhance the salient features of speech is described and its efficacy is evaluated. The Contrast Enhancement (CE) algorithm implements dynamic compressive gain and lateral inhibitory sidebands across channels in a modified winner-take-all circuit, which together produce a form of suppression that sharpens the dynamic spectrum. Normal-hearing listeners identified spectrally smeared consonants (VCVs) and vowels (hVds) in quiet and in noise. Consonant and vowel identification, especially in noise, were improved by the processing. The amount of improvement did not depend on the degree of spectral smearing or talker characteristics. For consonants, when results were analyzed according to phonetic feature, the most consistent improvement was for place of articulation. This is encouraging for hearing aid applications because confusions between consonants differing in place are a persistent problem for listeners with sensorineural hearing loss

Characteristics of Hearing-Impaired Children in the Public Schools

Psychoeducational data were collected from the files of 1,250 hearing-impaired children in Iowa public schools in an effort to identify educational and linguistic profiles related to different degrees of hearing loss. The files of most mildly to moderately hearing-impaired children do not reflect complete assessment of language, academic, or intellectual skills even when support services are being provided. The data reveal deficits that often are inconsistent with the reports and patterns of achievement on which the allocation of support services for hearing-impaired children have been based. The appropriateness of many of the assessment tools in use is questionable.</jats:p