FRIDAY MORNING, 20 MAY 2005 REGENCY E, 8:30 A.M. TO 12:00 ...

5aPP3. Comparing linear regression models applied to psychophysical
data. Zhongzhou Tang, Virginia M. Richards Dept. of Psych., Univ. of
Pennsylvania, Philadelphia, PA 19104, richards@psych.upenn.edu, and
Andrew Shih Univ. of Pennsylvania, Philadelphia, PA 19104
Relative weights for a profile analysis task were obtained using four
regression/classification models; correlation coefficients, linear regression,
logistic regression and probit regression. The aim of the study was to
examine the impact of the choice of model on the accuracy and the efficiency
with which the relative weights were determined. A yes/no task was
used with observers indicating whether or not there was an increment in
level to the central component of an 11-component standard. On each
presentation the amplitudes of the individual components of the complex
were randomly perturbed using draws from a normal distribution. When a
large number of trials 1250 were used to estimate the relative weights,
the four methods generated nearly identical weight estimates. When
smaller numbers of trials were used 112, the different methods generated
patterns of relative weights that were largely similar, and the patterns
deviated only modestly from the large-number solution. In terms of efficiency,
the error boundaries of the different methods were nearly indistinguishable.
All in all, the number of trials needed to obtain statistically
significant weights is sufficiently large that there is no apparent advantage
of using one method over the others. Work supported by NIH/NIDCD.
5aPP4. The difference in auditory memory between young and aged
listeners with normal hearing. Bruce Schneider, James Qi Dept. of
Psych., Univ. of Toronto at Mississauga, Mississauga, ON, Canada L5L
1C6, bschneid@credit.erin.utoronto.ca, Juan Huang, Xihong Wu, and
Liang Li Peking Univ., Beijing 100871, China
The perceptual fusion of a noise with its delayed copies implies that
there is a memory for maintaining a detailed representation of an arbitrary
waveform. This auditory memory would be important for perceptually
grouping correlated sounds and segregating uncorrelated sounds in noisy,
reverberant environments, in which older listeners find it much more difficult
than younger listeners to process signals. To determine the temporal
extent of the auditory memory and whether it is affected by aging, this
study investigated the detection of a break in correlation between two
correlated broadband noises in younger and older listeners with normal
hearing. The results show that younger listeners could detect a 100-ms
break in correlation up to interaural delays ranging from 6.3 to 23.0 ms,
suggesting that higher-order central mechanisms beyond the brainstem
delay lines are likely to be involved in maintaining a memory trace of the
fine details of the acoustic waveform. Aged listeners, however, could detect
the break up to interaural delays ranging only from 6.7 to 9.7 ms,
indicating the age-related decline in auditory memory. This decline may be
one of the main causes leading to perceptual difficulties experienced by
older listeners in noisy, reverberant environments. Work supported by
NSERCC and MSTC.
5aPP5. About the neglected auditory abilities within psychological
tests of intelligence. Jenny Papenbrock, Kristin Seidel, Susanne Weis,
and Heinz-Martin Suess Dept. of Psych., Univ. of Magdeburg, Pfaelzer
Platz, Geb. 24, Postfach 4120, 39016 Magdeburg, Germany,
si-projekt@gse-w.uni-magdeburg.de
Auditory abilities play an important role in human intellectual abilities.
In his model of human cognitive abilities Carroll 1993 identified a separate
domain of auditory ability. Despite their theoretical and practical relevance,
these abilities were mainly excluded in psychological tests. In
order to compensate for this lack we developed a test which is intended to
complement existing intelligence tests. To measure general auditory abilities
already existing materials Stankov and Horn, 1980 were used along
with newly developed auditory tasks. Our test includes nonverbal tasks
containing only tones as well as auditory textual tasks using spoken words.
We expect that the auditory tasks measure a separate ability and therefore
can make an important contribution to complement already existing intelligence
tests. To demonstrate that the test is able to measure different
aspects of auditory abilites pure tone tasks should be distinguishable from
auditory textual tasks. 120 subjects worked on the auditory test as well as
on a well-established test of intelligence Test for the Berlin Intelligence
Structure Model, BIS-4; Jger, S & Beauducel, 1997 which operates with
written, numerical and figural material. Main results of our study are reported
and implications for future research concerning psychological ability
tests are discussed.
5aPP6. Contributions of individual components to the overall
loudness of a multi-tone complex. Lori Leibold, Samar Khaddam, and
Walt Jesteadt 555 North 30th St., Omaha, NE 68131,
leiboldl@boystown.org
The contributions of individual components to the overall loudness of
a multi-tone complex were examined in a two-interval, loudness-matching
task. Stimuli were five-tone complexes centered on 1000 Hz, with six
different logarithmic frequency spacings, ranging from a frequency ratio
of 1.012 to 1.586. Stimuli were presented for 300 ms 10 ms rise/fall. The
overall level of the standard complex was fixed at 60 dB SPL 53 dB/
component. Levels of the individual components of the comparison complex
were selected at random from a rectangular distribution with a range
of 20 dB. Ten 100-trial blocks were run for each frequency-spacing condition.
Perceptual weights were computed by calculating the point-biserial
correlation between the difference in the level of each component across
the two intervals and the subjects response. When all components fell
within the same critical band, weights varied little across components. In
contrast, the range of weights increased with increasing frequency separation,
with increasing weight given to the lowest and highest frequency
components. The audibility of individual components was determined by
measuring detection thresholds for each component in the presence of the
remaining four components. A strong relation between component weight
and audibility was observed for all but the narrowest spacing conditions.
5aPP7. Differences in loudness of tone complexes with positive and
negative Schroeder phase. Manfred Mauermann and Volker Hohmann
Medizinische Physik, Institut fr Physik, Fakultt V, C.v.O Universität
Oldenburg, 26129 Oldenburg, Germany
Tone complexes with positive (m) and negative Schroeder phase
(m) have an identical long-term spectrum, the same temporal envelope
but are inverted in time. They show large differences in masking efficiency
most probably being related to a different cochlear representation. The
current study investigates to which extent loudness perception is affected
similarly by the different phase characteristic of m/m stimuli. Therefore,
the loudness of m/m stimuli 1.6 octave bandwidth was
matched in seven normal hearing and three hearing impaired subjects. In
the first experiment the fundamental frequency f 0 of the tone complexes
was varied from 2–1536 Hz for different center frequencies at a soft level
of the reference signal (m). In normal hearing subjects the m stimuli
needa6dBhigher level to be perceived as equally loud as the respective
m stimuli for f 0 in the range of 24–96 Hz. In the second experiment
the difference in loudness of m/m was investigated as function of the
of the reference-stimulus level 5–80 dB SL at a center frequency of
2660 Hz and f 0 at 48 Hz. The largest differences in loudness were found
for levels between 40–60 dB, clearly reduced for higher and lower levels
of the reference stimulus.
5a FRI. AM
2597 J. Acoust. Soc. Am., Vol. 117, No. 4, Pt. 2, April 2005 149th Meeting: Acoustical Society of America 2597