Ira M. Ventry1, Robert W. Woods1, Martha Rubin2, Wathina Smith Hill3
1Teachers College, Columbia University, New York, New York 10027
2Lexington School for the Deaf, New York, New York 11370
3Veterans Administration Hospital, Bronx, New York 10468
Tóm tắt
Most comfortable loudness (MCL) levels for pure tones, broad- and narrow-band noise, and connected speech were studied in three independent experiments using Békésy audiometers and young normal-hearing males and females. Differences in MCL were explored as a function of attenuation rate, sex, frequency of the pure-tone and narrow-band stimuli, interrupted versus continuous pure-tone stimuli, instructional set, session, and a modified Békésy operation which allowed the subject to hold intensity constant over time versus standard Békésy operation. There were no significant sex, set, session, or operation differences. In all three experiments, a 2.5-dB/sec attenuation rate produced higher MCLs than a 1.25-dB/sec rate. In general, a 500-Hz tone or narrow-band noise centered at 500 Hz was tracked at the highest sound-pressure levels (SPLs), while broad-band noise was consistently tracked at the lowest levels. Regardless of frequency or attenuation rate, continuous pure tones were tracked at higher SPLs than interrupted pure-tone stimuli. Although intersubject variability was relatively high, the majority of test-retest differences in each experiment was 10 dB or less. Over-all MCLs in decibels SPL re 0.0002 μbar were 49.3 for speech, 49.4 for noise, and 51.7 for pure tones.
