A subjective evaluation of signal-noise ratio and/or reverberation times and their effects on speech discrimination

For selection of assistive hearing devices and directive products to be used in a classroom sound environment

Abstract

Assistive listening devices that can improve the sound environment of a classroom are necessary for students with impaired hearing.
We evaluate that RASTI that was appreciable combination between Signal-Noise ratio (SNR) and the reverberation time (RT) was assumed to be an index and a tendency to the speech discrimination and subjective evaluation under noise and/or reverberation time for selection the assistive listening devices and improving sound environment for the students in the class room.
Our results showed a correlation between sentence discrimination levels and RASTI, and when reverberation time was adjusted to 0 seconds, all subjects' evaluations improved.
The necessity that was examined when we select assistive hearing device, digital hearing aid with directional microphone and FM system that can improve RT, we must consider not only SNR but also RT.