Abstract:
J Acoust Soc Am. 2013 Jan;133(1):365-76. doi: 10.1121/1.4768798.
Spectral timbre perception in ferrets: Discrimination of artificial
vowels under different listening conditions.
Bizley JK, Walker KM, King AJ, Schnupp JW.
Source
Department of Physiology, Anatomy and Genetics, University of Oxford,
Parks Road, Oxford OX1 3PT, United Kingdom.
Abstract
Spectral timbre is an acoustic feature that enables human listeners to
determine the identity of a spoken vowel. Despite its importance to
sound perception, little is known about the neural representation of
sound timbre and few psychophysical studies have investigated timbre
discrimination in non-human species. In this study, ferrets were
positively conditioned to discriminate artificial vowel sounds in a
two-alternative-forced-choice paradigm. Animals quickly learned to
discriminate the vowel sound /u/ from /[lower epsilon]/ and were
immediately able to generalize across a range of voice pitches. They
were further tested in a series of experiments designed to assess how
well they could discriminate these vowel sounds under different
listening conditions. First, a series of morphed vowels was created by
systematically shifting the location of the first and second formant
frequencies. Second, the ferretswere tested with single formant stimuli
designed to assess which spectral cues they could be using to make
their decisions. Finally, vowel discrimination thresholds were derived
in the presence of noise maskers presented from either the same or a
different spatial location. These data indicate that ferretsshow robust
vowel discrimination behavior across a range of listening conditions
and that this ability shares many similarities with human listeners.
PMID: 23297909 [PubMed - in process]
End quote.
We actually find hearing ferrets to be very good at coming to
understand speech, too, as long as there is consistent repetition
of words in context, reward involved, and the sentence structure is
simple, though we have had some whose behavior indicated understanding
of conditionals. An example of conditionals was when we knew that kit,
Warp, had fallen asleep somewhere but did not know where. Steve
repeated to Meltdown a number of times, "Meltdown get Warp, then
Meltdown get treat." and when she looked like may be she had gotten
it he put her down. She ran under our platform bed, emerged dragging
our Warp by the scruff, deposited Warp on Steve's foot, and then
looked up at Steve and licked her chops.
Ferrets are descended from animals with activity that is mostly
crepuscular (low light conditions of dawn and dusk) and also much
activity in dark burrows for living and hunting -- so like smell and
touch, the processing of sounds had to be very important and being able
to tell differences in the sounds and complex sound patterns of den
mates, multiple types of prey, and some predators who might join the
polecats below ground all would affect polecat survivability.
Ninety-nine results results come up with the search term
ferret sound
http://www.ncbi.nlm.nih.gov/pubmed?term=ferret%20sound
and 57 come up with
ferret hearing
http://www.ncbi.nlm.nih.gov/pubmed?term=ferret%20hearing
Sukie (not a vet) Ferrets make the world a game.
Recommended ferret health links:
http://pets.groups.yahoo.com/group/ferrethealth/
http://ferrethealth.org/archive/
http://www.miamiferret.org/
http://www.ferrethealth.msu.edu/
http://www.ferretcongress.org/
http://www.trifl.org/index.shtml
http://homepage.mac.com/sukie/sukiesferretlinks.html
all ferret topics:
http://listserv.ferretmailinglist.org/archives/ferret-search.html
"All hail the procrastinators for they shall rule the world tomorrow."
(2010, Steve Crandall)
A nation is as free as the least within it.
[Posted in FML 7667]
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