Perception of rise/fall times

["Dennis P. Phillips, Ph.D." <ears@xxxxxxxxx>]

Hi Everyone:

I'd like to thank all who responded to my recent question about asymmetries
in the perceptual effects of rise and fall times.  The responses were
diverse, thoughtful, informative, and often pointed me to references which
I had not previously found.  This has been very helpful indeed. Again, many
thanks.

For folks who are interested, a "potted" summary would go something like
this.  Sounds with fast onsets and slow decays are judged as louder than
their time-reversed analogs.  Sinusoids with exponential onsets (ramped
sinusoids) have a more tonal quality, and a less hollow, percussive one,
than their time-reversed counterparts (damped sinusoids).  Normal listeners
are more sensitive to switching transients at the onset of a tone than to
those at its offset.  Thresholds for amplitude decrement detection are
comparable to those for increment detection if the decrement is not too
short in duration.  Rise times (plucks and bows) are not perceived
categorically.  In general, these findings point to the perceptual
importance of stimulus onsets (or increments).  Below are a few of the
references.

All best wishes.  Cheers,

Dennis



Irino, T. and Patterson, R.D.  (1996)  Temporal asymmetry in the auditory
system.  J. Acoust. Soc. Am., 99: 2316-2331.
Miyasaka, E.  (1980)  Detectability of switching transients. NHK
Laboratories Note No. 275.  (abstract).  Tokyo, Japan: NHK Science &
Technical Research Labs.
Oxenham, A.J.  (1997)  Increment and decrement detection in sinusoids as a
measure of temporal resolution.  J. Acoust. Soc. Am., 102: 1779-1790.
Patterson, R.D.  (1994a)  The sound of a sinusoid: spectral models.  J.
Acoust. Soc. Am., 96: 1409-1418.
Patterson, R.D.  (1994b)  The sound of a sinusoid: Time-interval models.
J. Acoust. Soc. Am., 96: 1419-1428.
Rosen, S.M. and Howell, P.  (1981)  Plucks and bows are not categorically
perceived.  Percept. Psychophys., 30: 156-168.
Stecker, G.C. and Hafter, E.R.  (2000)  An effect of temporal asymmetry on
loudness.  J. Acoust. Soc. Am., 107: 3358-3368.


-----------------------------------
Dennis P. Phillips, Ph.D.
Hearing Research Laboratory
Professor,
Department of Psychology
Dalhousie University
Halifax, NS, Canada  B3H 4J1
Phone: (902)494-2383
Fax:   (902)494-6585
E-mail: ears@is.dal.ca
-----------------------------------