Interaural correlation discrimination: I. Bandwidth and level dependence

Abstract

Measurements of interaural cross-correlation jnds from two reference correlations at several bandwidths were obtained for constant-total-power and constant-spectral-power Gaussian noise. At a reference correlation of 1, the results indicate that for bandwidths less than or equal to 115 Hz the jnd remains at a constant value of approximately 0.004, and monotonically increases (discrimination performance degrades) to approximately 0.04 as bandwidth increases above 115 Hz. At a reference correlation of 0, the jnd decreases (discrimination performance improves (from approximately 0.7 to 0.35 as the bandwidth increases from 3 to 115 Hz, and remains at a constant value of approximately 0.35 for bandwidths greater than 115 Hz. A decrease in the spectral level causes an increase in the jnds at a reference correlation of 1, and no change in the jnds at a reference correlation of 0. Of the three models tested, none is able to completely describe all of the empirical results.

Sensitivity to interaural envelope correlation changes in bilateral cochlear-implant users

“…2,5,6,and 7). NH listeners are extremely sensitive to changes in correlation from a perfectly correlated reference but much worse at detecting changes from a decorrelated references (Gabriel and Colburn, 1981;Koehnke et al, 1986;Culling et al, 2001;Goupell, 2012;Goupell and Litovsky, 2014). Thus a parsimonious explanation for our data is that some of our CI listeners are not necessarily less sensitive than NH listeners in this task, but they are demonstrating a typical finding, which is reduced sensitivity to changes in envelope correlation because of the internal decorrelation in the neural representation of the signals.…”

The role of envelope statistics in detecting changes in interaural correlation

“…Human listeners are typically very sensitive to differences in signals between the ears or interaural decorrelation (e.g., Gabriel and Colburn, 1981). Decorrelation can be introduced by adding an out-of-phase target (Sp) to a diotic noise background (No), as is used in binaural masking-level difference (BMLD) experiments.…”

Decorrelation Sensitivity of Auditory Nerve and Anteroventral Cochlear Nucleus Fibers to Broadband and Narrowband Noise

“…Most TB fibers (68 of 106) yield lower thresholds than AN fibers. The two boxes show the range of reported human decorrelation jnds from base correlation 1 for narrowband noise at 500 Hz (Pollack and Trittipoe, 1959a;Gabriel and Colburn, 1981;Koehnke et al, 1986) and 4 kHz (Koehnke et al, 1986). The black horizontal lines in the rectangles show the medians of reported thresholds.…”

“…Figure 11 shows ⌬ thresholds toward correlation 1, from base correlation ϭ 0. The box shows the range of reported human correlation jnds from base correlation 0 (Gabriel and Colburn, 1981;Boehnke et al, 2002); the black horizontal line shows the median of the reported thresholds. When compared with thresholds from base 1, thresholds from base 0 show a similar CF dependence, are generally higher, and exhibit smaller differences between AN and TB fibers.…”

“…In psychoacoustic studies, sensitivity to interaural correlation has been measured extensively and systematically by mixing independent noise sources (Pollack and Trittipoe, 1959a;Gabriel and Colburn, 1981;Koehnke et al, 1986;Bernstein and Trahiotis, 1996;Culling et al, 2001;Boehnke et al, 2002). Single-neuron sensitivity to such stimuli, in which the normalized correlation is the primary parameter varied, has received little attention.…”