ASA 14 - Influence Of Masking Noise On Pitch


The pitch of a tone is influenced by the presence of masking noise or another tone near to it in frequency. If the interfering tone has a lower frequency, an upward shift in the test tone is always observed. If the interfering tone has a higher frequency, a downward shift is observed, at least at low frequency (< 300 Hz). Similarly, a band of interfering noise produces an upward shift in a test tone if the frequency of the noise is lower (Terhardt and Fastl, 1971).

In this demonstration, a 1000-Hz tone, 500 ms in duration and partially masked by noise low-pass filtered at 900 Hz, alternates with an identical tone, presented without masking noise. The tone partially masked by noise of lower frequency appears slightly higher in pitch (do you agree?). When the noise is turned off, it is clear that the two tones were identical.


B.Scharf and A.J.M.Houtsma (1986), "Audition II: Loudness, pitch, localization, aural distortion, pathology," in Handbook of Perception and Human Performance, Vol. 1, ed. K.R.Boff, L.Kaufman, and J.P.Thomas (J. Wiley, New York).

E.Terhardt and H.Fastl (1971), "Zum Einfluss von Stortonen und Storgerauschen auf die Tonhohe von Sinustonen," Acustica 25, 53-61.

Time Delay


A partially masked 1000-Hz tone alternates with an unmasked 1000-Hz comparison tone. Compare the pitches of the two tones.