ASA 124th Meeting New Orleans 1992 October

3pPP9. Pure-tone thresholds in unmodulated and modulated noise for elderly listeners with normal or near-normal audiograms.

R. W. Peters

Speech and Hear. Sci., Dept. of Med. Allied Health Professions, Univ. of North Carolina, Chapel Hill, NC 27599-7190

J. W. Hall, III

Univ. of North Carolina, Chapel Hill, NC 27599-7190

Thresholds for the detection of a 1.0-kHz tone were measured in modulated and unmodulated noise for 11 elderly listeners, aged 62--83 with normal or near-normal audiograms, and for 5 younger normally hearing subjects. The noise was either narrow band, 1 ERB, or wide band, 1000 Hz, centered at 1000 Hz. The noise was either unmodulated or modulated at 10, 20, 30, 40, and 50 Hz. Auditory filter shapes were also estimated for the elderly subjects at 800, 1000, and 2000 Hz. Detection thresholds were significantly higher for the elderly as compared to the younger listeners for both unmodulated noise and narrow and wide-band-modulated noise. Improvement in detection in fluctuating as opposed to steady-state, unmodulated, noise was similar for the elderly listeners to that for younger listeners. Detection thresholds were not significantly correlated with auditory bandwidths or other auditory filters characteristics. There was an age effect beginning about age 75, in that pure-tone thresholds in both unmodulated and modulated noise, became progressively elevated. [Research supported NIDCD and the Andrus Foundation.]