Gr. Kidd et Cs. Watson, DETECTION OF FREQUENCY CHANGES IN TRANSPOSED SEQUENCES OF TONES, The Journal of the Acoustical Society of America, 99(1), 1996, pp. 553-566
The ability to detect frequency changes in transposed sequences of ton
es was examined in a series of seven experiments. Listeners were asked
to judge which of two transposed (i.e., frequency-shifted) comparison
patterns preserved the sequence of relative frequencies presented in
a preceding standard pattern. The task was performed with five-tone an
d two-tone patterns under conditions of high and minimal pattern uncer
tainty. Regardless of pattern length. or level of uncertainty, frequen
cy discrimination thresholds for a change in the relative frequency df
a single tone were considerably higher when patterns were transposed
than when they were not. There was a tendency for performance to worse
n with increasing degrees of transposition (primarily under high uncer
tainty) but most of the detrimental effects of transposition occurred
within the first two semitones of transposition. Minimal uncertainty t
esting resulted in large improvements with five-tone patterns (as much
as one order of magnitude), but there was no effect of level of uncer
tainty on performance with two-tone patterns. Thresholds for changes i
n two-tone patterns were similar to (although slightly higher than) th
ose for five-tone patterns under minimal-uncertainty testing. This pat
tern of results reveals that the effects of stimulus complexity (seque
nce length) and pattern familiarity (level of uncertainty) on relative
-frequency discrimination are quite similar to the effects of these va
riables on absolute-frequency discrimination. (C) 1996 Acoustical Soci
ety of America.