NEW COMPUTERIZED FINNISH SPEECH IN NOISE TEST AND BINAURAL HEARING

Aided and unaided binaural versus monaural recognition of speech has b een studied with more or less laborious methods when speech and noise sources are spatially separated. The efficacy of the new Finnish speec h in noise test to show binaural advantage was evaluated in free field conditions. Thirteen subjects with normal hearing were tested measuri ng speech recognition thresholds in noise (SRTN) in anechoic chambre w ith different situations of spatial separation of speech and noise sou rces monaurally and binaurally. The noise source was fixed above the h ead (treating both ears similarly) and equidistant speech was delivere d at different azimuths. SRTNs with mixed speech and noise without spa tial separation served as normalizing reference. Differencies in SRTNs consistently followed the changing head and pinna shadow effects on t he speech-to-noise ratio with a smaller binaural advantage. This new t est seems to give quite economically the same results as those of prev ious more sophisticated investigations on speech recognition in free f ield situations.