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In response to the query from Nikki Rikard, the TBAC was originally
developed in 1982, but was only described in a couple of abstracts. We
hesitated to publish our findings at the time. While the most interesting
result was the low correlations between speech recognition and measures of
spectral-temporal acuity, the TBAC speech measures were insufficient to
support any strong conclusion about there being distinct auditory abilities for
processing speech and nonspeech stimuli. Quite a bit later, Aimee
Surprenant and I extended the TBAC to include several additional speech tests,
got the same result, and did publish it. Humes and Christopherson also ran
some reliability tests on the TBAC and found it to be a relatively stable
battery. Most recently Kidd, Gygi and I further extended the TBAC
to include some other psychoacoustic measures (gap detection, gap discrimination,
SAM noises, ripple noise) and environmental sounds, and using factor analyses
found speech and environmental sound recognition to be grouped in a common
factor, while three other factors included various measures of spectral-temporal
acuity…that work is under review. Our general conclusion now is
that a great deal of the variance in familiar sound recognition (we call it the
“FSR Ability”) reflects not spectral-temporal acuity, but the
ability to recognize auditory wholes on the basis of fragments…some listeners
need more fragments than others. Grossly deficient spectral or
temporal acuity, as in the case of some hearing impaired listeners or by
normals listening to vocoded speech, is of course going to reduce recognition
performance. But the great majority of listeners with normal audiograms
have sufficient spectral-temporal acuity that their recognition scores appear to
be limited by their FSR skills rather than by their differential acuity. Among
other things this means that speech is a dandy code, since a considerable
range of spectral and temporal resolving power has little impact on our ability
to process it. Chuck Watson Surprenant, A. M. and Watson, C.S. (2001) Individual differences
in the processing of speech and
nonspeech sounds by normal-hearing listeners. J. Acoust. Soc. Am., 110, 2085-95. Humes, L. E.
and Christopherson, L. A. (1992) Some Psychometric Properties of the Test of
Basic Auditory Capabilities (TBAC) Journal
of Speech and Hearing Research 35 929-935. |