Geometrical displays of speech spectra as aids to lipreading
Steven L. Tait, William J. Strong · The Journal of the Acoustical Society of America · 1999
Many syllables are ambiguous to lip readers because of their similar appearance on the lips. An aid is necessary to make distinction of these syllables possible. In a previous study [E. J. Hunter and W. J. Strong, J. Acoust. Soc. Am. 102, 3166–3167 (1997)], speech spectra were processed at 5-ms intervals and displayed as sequences of irregular decagons. Subjects were asked to discriminate between pairs of decagons representing ambiguous syllables. Subjects successfully discriminated most pairs, but were inconsistent in discrimination of voiced-/unvoiced-stop pairs. This study is concerned with display formats aimed at improving discrimination of ambiguous pairs to develop a more effective aid for lip readers. In particular, ‘‘pie slice’’ and ray formats are evaluated against polygons. Filled shapes are evaluated against open shapes. Five-band speech spectra are evaluated against ten-band spectra. Display color is evaluated against line thickness for representing overall sound level.