Effects of temporal stimulus properties on the perception of across-frequency asynchrony

Abstract

The role of temporal stimulus parameters in the perception of across-frequency synchrony and asynchrony was investigated using pairs of 500-ms tones consisting of a 250-Hz tone and a tone with a higher frequency of 1, 2, 4, or 6 kHz. Subjective judgments suggested veridical perception of across-frequency synchrony but with greater sensitivity to changes in asynchrony for pairs in which the lower-frequency tone was leading than for pairs in which it was lagging. Consistent with the subjective judgments, thresholds for the detection of asynchrony measured in a threealternative forced-choice task were lower when the signal interval contained a pair with the lowfrequency tone leading than a pair with a high-frequency tone leading. A similar asymmetry was observed for asynchrony discrimination when the standard asynchrony was relatively small ( 20 ms) but not for larger standard asynchronies. Independent manipulation of onset and offset ramp durations indicated a dominant role of onsets in the perception of across-frequency asynchrony. A physiologically inspired model, involving broadly tuned monaural coincidence detectors that receive inputs from frequency-selective onset detectors, was able to accurately reproduce the asymmetric distributions of synchrony judgments. The model provides testable predictions for future physiological investigations of responses to broadband stimuli with across-frequency delays.

Effects of tonotopicity, adaptation, modulation tuning, and temporal coherence in “primitive” auditory stream segregation

“…This is consistent with earlier results from Uppenkamp et al (2001) who found a larger perceived "compactness" for click stimuli and downward chirps than for upward chirps that had been designed to produce the largest neural synchronization across frequency at cochlear level. Furthermore, the results are compatible with recent findings from Wojtczak et al (2012Wojtczak et al ( , 2013 where synchrony detection of pure tones with varying frequency separations was investigated. Wojtczak et al (2012Wojtczak et al ( , 2013 found indeed an asymmetry favoring low-frequency components lagging highfrequency components and proposed a higher-level process that slightly overcompensates for the cochlear delay differences across frequency.…”

Rhythm judgments reveal a frequency asymmetry in the perception and neural coding of sound synchrony

“…The neural and behavioral asymmetries observed in the present study are consistent with some earlier behavioral findings using just pure tones, which were separated by two octaves or more (14,15). The fact that these effects occur with such large separations (and when potential interference is eliminated with a masking noise spectrally located between the tones) rules out the explanations of mutual masking provided by Hove et al using an auditory model (8).…”

“…Interestingly, psychophysical studies in humans have shown that these physiologically documented delays are not perceived, with physically simultaneous sources generally being judged as simultaneous, despite their different delays in traveling through the auditory periphery (14,15). Moreover, the veridical perception of cross-frequency timing has been demonstrated at both very low [25 dB sound pressure level (SPL)] and high (85 dB SPL) sound levels (14,15), despite evidence that differences in cross-frequency cochlear delays may decrease with increasing level (23,25,29). Although the relative cochlear delays between low-and highfrequency sounds can vary depending on their intensities, the response to the low-frequency sound will always be slower, as illustrated by the three red lines in Fig.…”

Converging evidence that common timing processes underlie temporal-order and simultaneity judgments: a model-based analysis

“…These features permit direct tests of the model in within-subjects conditions, checking out the feasibility of accounting for the data under the assumption of identical timing processes across tasks. It should nevertheless be noted that timing parameters may vary greatly across sensory modalities (i.e., they will reasonably vary for visual, auditory, tactile, or vestibular stimuli due to specificities of peripheral processing and neural transmission along the corresponding pathways), across stimuli within the same sensory modality (e.g., due to the place-frequency map of the basilar membrane, low and high auditory frequencies reach their associated locations at different times; Uppenkamp, Fobel, & Patterson, 2001;Wojtczak, Beim, Micheyl, & Oxenham, 2012, Wojtczak et al 2013 Visual delay, Δt Prob. AF response Fig.…”