Binaural masking level difference for speech signals in noise

摘要

One of the fundamental demands on hearing protectors is a remaining ability to communicatewhile using them. Today hearing protectors with electronic communication systems are availableto meet this demand. When listening to a binaural signal in a masking noise, the ability to detectthe signal improves when there is a difference in phase between the left and the right ear signal.This study investigates the possibility to enhance speech intelligibility in electronic hearingprotectors by the psychoacoustic phenomenon binaural masking level difference. The binauralmasking level difference was investigated in both detection and recognition of speech embeddedin noise when the signal was phase-shifted 180 degrees between the left and the right ear.Spondaic words masked by noise were presented binaurally to ten normal hearing subjects. Theresults are presented in terms of speech detection threshold and a psychometric function ofspeech recognition versus signal-to-noise ratio. Both speech detection threshold and speechintelligibility improved when the speech signal was phase-shifted. The binaural intelligibilitylevel difference ranged from 5.7 to 7.7 dB. The improvement in speech intelligibility from aninteraurally phase-shifted speech signal could be valuable in a number of occupational situationssuch as aircraft cabin environments.