Speech tests as measures of outcome.

Speech tests comprise an important and integral part of any assessment of the effectiveness of intervention for hearing disability and handicap. Particularly when considering hearing aid services for adult listeners, careful consideration has to be given to the particular form and application of inferences drawn from speech identification procedures if erroneous conclusions are to be avoided. It is argued that four such components relate to the statistical properties and discriminatory leverage of speech identification procedures, the choice of presentation level and conditions in regard to the auditory environment experienced by hearing-impaired clients, the extent to which speech tests based on segmental intelligibility provide appropriate information in relationship to perceived disabilities and handicaps, and the ways in which speech identification procedures to evaluate the potential benefits of signal-processing schemes for hearing aids are dependent upon sufficient listening experiences. Data are drawn from the literature to illuminate these points in terms of application in clinical practice and clinical evaluation exercises, and also with regard to future research needs.