FREQUENCY PATTERN OF RESIDUAL MASKING BY PURE TONES MEASURED ON BEKESY AUDIOMETER

A Békésy audiogram for a 5 msec tone signal repeated once per second was obtained over the frequency range 100 10 000 Hz. The audiogram was repeated with a 100 msec masking tone preceding the signal by 10 msec. The masking tones were presented at 20 100 dB sensation levels (SLs). The results show that 250 and 500 Hz produce no masking at 20 dB, but the greatest over all masking, without sharply defined maxima, occurs at higher SLs. Maskers of 1000, 2000, and 4000 Hz produce masking at the 20 dB level. At the low levels, there is a clear peak at the masking frequency; but as the masker level is raised, this peak begins to shift to increasingly higher frequencies, although it never reaches the second harmonic. © 1969, Acoustical Society of America. All rights reserved.