Papers selected by Waka Fujisaki
■Observation of a reversible,
medication-induced change in pitch perception.
■The origin of tonality and a possible explanation of the
octave enlargement phenomenon.
■Auditory filter shapes derived with noise stimuli
■A time domain description for the pitch strength of iterated
rippled noise
■Effects of differences in timbre on sequential grouping
Observation of a reversible, medication-induced
change in pitch perception.
Vladimir Chaloupka, Stephen Mitchell and Richard Muirhead J. Acoust.
Soc. Am. 96 (1), July 1994
This paper reports a study of an absolute pitch possessor who, upon administration of the psychoactive drug Tegratol (carbamazepine), experienced a significant change in her pitch perception. The subject’s performance both in producing, as well as inidentifying, random-frequency tones was measured, covering the period of administration of the drug, as well aw control periods before and after. The main effect of the drug was a downward shift of the perceived pitch as compared to the two control periods. The magnitude of the shift was observed to increase with increasing fundamental frequency of the stimulus: the average shift was about one semitone. Detailed results on the frequency dependence and time dependence of the pitch shifts are presented. This may be the first documented reports of a significant, reversible change of pitch perception caused by a medication.
The origin of tonality and a possible explanation of
the octave enlargement phenomenon.
Kengo ohgushi J. Acoust.
Soc. Am. 73 (5), May 1983
It is known that the subjective octave is slightly larger than the physical octave (=2) for a variety of tones. This paper presents a new idea about the physiological origin of tonality, and a new theory founded on recent knowledge of the auditory physiology, to explain the octave enlargement phenomenon for pure tones. The theory’s predictions of the subjective octave agree well with psychophysical data.
Auditory filter shapes derived with
noise stimuli
Roy D. Patterson J. Acoust.
Soc. Am., 59, No3, March 1976
A wide-band noise having a deep notch with sharp edges was used to mask a tone. The notch was centered on the tone, and threshold was measured as the width of the notch was increased from 0.0 to 0.8 times the tone frequency (0.5, 1.0, or 2.0 kHz). The spectrum level of the noise was 40 dB SPL. If it is assumed that the auditory filter is reasonably symmetric at these intensities, then the shape of the filter centered on the tone can be estimated from the first derivative of the curve relating tone threshold to the width of the notch in the noise. The 3-dB bandwidths of the filters obtained were about 0.13 of their center frequency. In the region f the passband, the Gaussian curve provides a good approximation to the shape of the derived filters. The equivalent rectangular bandwidths of the Gaussian approximation are about 0.20 of their center frequency, which is comparable to the critical-band estimates of R. Zwicker, G. Flottorp. And S.S. Stevens [“Critical bandwidth in loudness summation,” J. Acoust. Soc. Am. 29, 548-557 (1957)]. The Gaussian approximation cannot be used outside the passband, because the tails of the derived filters do no fall as fast as the Gaussian curve.
A time domain description for the pitch
strength of iterated rippled noise
William A. Yost, Roy Patterson and Stanley Sheft J. Acoust.
Soc. Am., 99(2), February 1996
Two versions of a cascaded add, attenuate, and delay circuit were used to generate iterated rippled noise (IRN) stimuli. IRN stimuli produce a repetition pitch whose strength relative to the noise can be varied by changing the type of circuit, the attenuation, or the number of iterations in the circuit. Listeners were asked to discriminate between various pairs of IRN stimuli which differed in the type of network used to generate the sounds or the number of iterations (n=1,2,3,4,7 and 9). Performance was determined for IRN stimuli generated with delays of 2,4, and 8 ms and for four bandpass filter conditions (0-2000, 250-2000, 500-2000, and 750-2000Hz). Some IRN stimuli were extremely difficult to discriminate despite relatively large spectral differences, while other IRN stimuli produced readily discriminable changes in perception, despite small spectral differences. These contrasting resuls are inconsistent with simple spevtral explanations for the perception of IRN stimuli. An explanation based on the first peak of the autocorrelation function of IRN stimuli is consistent with the results. Simulations of the processing performed by the peripheral auditory system (i.e., interval histograms and correlograms) produce results which are consistent with the involvement of these temporal processes in the perception of IRN stimuli.
Effects of differences in timbre on
sequential grouping
Rhodri Cusack and Brian Roberts
Perception & Psychophysics 2000, 62(5), 1112-1120
Differences in the timbre of sounds in a sequence can affect their perceptual
organization. Using a performance measure, Hartmann and Johnson (1991) concluded
that streaming could be predicted primarily by the extent to which sounds were
passed by different peripheral channels. However, results from a rating task
by Dannenbring and Bregman (1976) suggested that sounds in the same spectral
region (passed by the same peripheral channels) can be allocated to different
streams. In Experiment 1, it was found, using an interleaved melody task, that
target sounds could be selected from distracters in the same spectral region
more easily when they differed in timbre. This finding might result from primitive
stream segregation or schema-driven selection, but not from peripheral channeling.
In Experiment 2, a rhythm discrimination task was used, requiring the sounds
to be integrated for good performance. Differences in timbre impared performance,
indicating the occurrence of primitive stream segregation.