Arrays Of Rectangular Subcritical Speech Bands: Intelligibility Improved By Noise-Vocoding And Expanding To Critical Bandwidths

A previous study [Warren, Bashford, and Lenz (2017). J. Acoust. Soc. Am. 141, EL222-EL227] reported that arrays of subcritical width rectangular speech bands can produce near ceiling sentence intelligibility. The present study used noise-vocoded subcritical band speech arrays with analysis bandwidths of 4%, 2%, 1%, or 0.5% of center frequency. Intelligibility decreased when analysis and noise carrier bandwidths were matched. However, expanding carrier noise bandwidths to a critical bandwidth of 1/3-octave (26%) produced array intelligibilities either equaling or substantially exceeding that of the original speech band arrays. Implications concerning bandwidth requirements of envelope processing and the redundancy of envelope cues are discussed. (C) 2018 Acoustical Society of America