抄録
The quality of sound through a hearing aid in hearing impaired persons was much different from that in normal subjects. Some experiments about agreeable reception and preference for quality of tones were performed.
Method: Four different test tones generated through the following circuits were given to normal subjects and hard of hering patients, and the difference between the paired tones was discriminated. The circuits were,
1) A circuit having a peak at 1, 000Hz.
2) A circuit having somewhat a similar characteristic to
1) circuit and having six band pass filters.
3) A circuit having a peak at 2, 000Hz.
4) A circuit having somewhat a similar characteristic to
3) circuit and having six band pass filters.
The method of pair comparisons was used. Tones from circuit 1) and 2), 3) and 4) were made pairs for the agreeable reception judgement. For the preference, circuits 1) and 3) were made a pair.
Conclusion:
As to the agreeable reception, about a half of the normal subjects discriminated the difference of tones but hard of hearing patients was unstable in response and almost failed in discriminating the difference.
As to the preference of the quality of tones, normal subjects selected the tone with a peak at 1, 000Hz, whereas the hard of hearing patients selected the one with a peak at 2, 000Hz.
These experiments suggested that it was questionable to decide the quality of hearing aid by a judgment by the normal subjects or by the electrophysical characteristics.
