Effect of roving on spatial release from masking for
amplitude modulated noise stimuli
Norbert Kopco, Jaclyn J. Jacobson, and Barbara G.
Shinn-Cunningham
A previous study investigating detection of broadband
signals embedded in broadband noise showed that detection thresholds depended
both on the temporal structure of the target and masker and their simulated
spatial locations [Kopco and Shinn-Cunningham, J. Acoust.
Soc. Am. 117, 2396, 2005].� The current study extends this work by
introducing a rove in overall intensity to reduce the reliability of overall
intensity cues for detecting the target.
Detection thresholds were measured for a broadband noise
target spectrally and temporally centered within a broadband noise masker.
Thresholds were measured for all combinations of six spatial configurations of
target and masker and five modulation conditions (all combinations of target
modulated and unmodulated and of masker modulated and
unmodulated; when both target and masker were
modulated, the modulation could either be equal or pi out of phase). The
amplitude modulation, if present, had a rate of 40 Hz and depth of 0.5. The
masker level was roved by +/-5dB between intervals within a trial.
Results suggest that the cues underlying target detection
depend on both the spatial configuration of target and masker and their temporal
structure, but� that,
when available, overall intensity cues also contribute to a target detection.
[Work supported by NSF and ONR]
