Room acoustics for the aged

This article deals with the combined effects of noise and reverberation on the speech-reception threshold for sentences. It is based on a series of current investigations on: (1) the modulation-transfer function as a measure of speech intelligibility in rooms, (2) the applicability of this concept to hearing-impaired persons, and (3) hearing loss for speech in quiet and in noise as a function of age. It is shown that, generally, in auditoria, classrooms, etc. the reverberation time T, acceptable for normal-hearing listeners, has to be reduced to (0.75)DT in order to be acceptable for elderly subjects with a hearing loss of D dB for speech in noise; for listening conditions as in lounges, restaurants, etc. the corresponding value is (0.82)DT.