Demonstrations of
Auditory Illusions and Tricks
2nd Edition
VI. Time Perception
<23> Interaural and
Monaural Tempo Difference
First, a series of short tones is presented monaurally
at a rate of 8 tones/second, immediately followed by a
similar sequence of tones presented interaurally.
Although both series are presented at identical rates, the
interaurally presented series sounds subjectively slower.
This demonstrates that a sequence of auditory events that
is alternated between the ears is stretched out in
auditory memory, as compared with non-alternating
sequences.
Previous studies revealed that the perceptual onset
asynchronies of these monaural and interaural
sequences differ by about 25 ms.
ten Hoopen, G., Vos, J., & Dispa, J. (1982).
Interaural and monaural clicks and clocks:
Tempo difference versus attention switching.
Journal of Experimental Psychology: Human
Perception and Performance, 8, 3, 422-434.
Akerboom, S., ten Hoopen, G., Olierook, P., &
van der Schaaf, T. (1983).
Auditory spatial alternation transforms auditory time.
Journal of Experimental Psychology:
Human Perception and Performance, 9, 6, 882-897.
<24> Overestimation of a Divided
Time Interval
When an empty duration of 240 ms marked by two short tone bursts is
divided into two empty parts by another tone burst, the whole
duration can be overestimated.
However, a clear overestimation
appears only when the listener perceives the divided duration as
divided.
A divided duration (a) and a non-divided (empty) duration (b)
can be presented.
It may take time for these demonstrations to be presented
after you click the play buttons.
In order to compare (a) and (b), please download the wave
files to your computer, and play alternately.
Hall, G.S. & Jastrow, J. (1886).
Studies of rhythm. Mind, 11,55-62.
Nakajima, Y. (1987).
A model of empty duration perception.
Perception, 16, 485-520
<25> Time-Shrinking
A short empty duration immediately preceded by an even shorter empty
duration can be underestimated.
Here, a fixed empty duration of 240 ms is immediately
preceded by another empty duration of 80-320 ms.
In the first presentation, the preceding duration is 320 ms,
and it is decreased in steps of 20 ms in the following
presentations.
The second duration is perceived as if it were shortened
when the preceding duration reached around 180 ms
(the eighth presentation).
Nakajima, Y., ten Hoopen, G., & van der Wilk, R. (1991).
A new illusion of time perception.
Music Perception, 8, 431-448.
Suetomi, D. & Nakajima, Y. (1998).
How stable is time-shrinking?
Journal of Music Perception and Cognition, 4, 19-25.
<26> A Discontinuous Change
in Time Perception Caused by Time-Shrinking
In the presentation of the first series (a), three sound markers
define two empty durations of 160 ms each.
The first duration is
decreased in steps of 10 ms, and the second duration is increased in
steps of 10 ms.
Thus, the total duration is fixed at 320 ms.
When the difference between the first and the second
duration is up to about 100 ms (the sixth pattern),
'time-shrinking', i.e., underestimation of the
second duration caused by the presence of the first duration,
takes place, and the two neighboring durations are perceived as
almost identical with each other.
When the physical difference between these
durations is enlarged further, time-shrinking disappears
rapidly, and the difference between the neighboring durations
is suddenly perceived clearly.
This kind of sudden change of percept does not
take place when the temporal order between the two
durations is reversed as in the second series (b).
Nakajima, Y., ten Hoopen, G., Hilkhuysen, G., & Sasaki, T. (1992).
Time-shrinking: A discontinuity in the perception of auditory
temporal patterns.
Perception & Psychophysics, 51, 504-507.
<27> Time-Shrinking in Patterns
Consisting of Three Empty Time Intervals
In the first presentation (the control condition), two
isolated empty durations of 240 ms are perceived as
almost equal to each other.
In all the other presentations, three neighboring empty durations, of
which the second and the third are fixed at 160 and 240 ms, are
followed by an isolated empty duration of 240 ms.
The first empty duration is 40 ms in the second presentation,
and increased in steps of 40 ms in the nine following
presentations.
The third empty duration is underestimated when the first
empty duration is 160 ms (the fifth presentation), about
300 ms (the eighth or ninth presentation), or above.
