FREQUENCY-WEIGHTING FUNCTIONS FOR BROAD-BAND SPEECH AS ESTIMATED BY ACORRELATIONAL METHOD

The relative contributions of various regions of the frequency spectru m to speech recognition were assessed with a correlational method [K. A. Doherty and C. W. Turner, J. Acoust. Soc. Am. 100, 3769-3773 (1996) ]. The speech materials employed were the 258-item set of the Nonsense Syllable Test. The speech was filtered into four frequency bands and a random level of noise was added to each band on each trial. A point biserial correlation was computed between the signal-to-noise ratio in each band on the trials and the listener's responses, and these corre lations were then taken as estimates of the relative weights for each frequency band. When the four bands were presented separately, the cor relations for each band were approximately equal; however, when the fo ur bands were presented in combination, the correlations were quite di fferent from one another, implying that in the broadband case listener s relied much more on some bands than on others. It is hypothesized th at these differences reflect the way in which listeners combine and at tend to speech information across various frequency regions. The frequ ency-weighting functions as determined by this method were highly simi lar across all subjects, suggesting that normal-hearing listeners use similar frequency-weighting strategies in recognizing speech. (C) 1998 Acoustical Society of America. [S0001-4966(98)07108-2]