Audio signals in electric home appliances evaluated in terms of the hearing ability of older adults.

Desirable properties for identification of auditory warning signals.

“…Our hearing will deteriorate in high frequency region when we get older [7]. From this viewpoint, the fundamental frequency should be settled lower than those used at present [8,9] and around 1 kHz seems to be appropriate [10].…”

A questionnaire survey on noise problems with elderly people

“…Also they are used at train stations. Sometimes it is said that it is not easy for elderly people to detect the signals since the frequency of signals is high [9] and the effect of background noise is considerable. The opinions about auditory warning signals were asked in Q4.…”