Resolvability of components in complex tones and implications for theories of pitch perception

Self Cite

Oxenham et al. [Proc. Nat. Acad. Sci. 101, 1421-1425 (2004)] reported that listeners cannot derive a "missing fundamental" from three transposed tones having high carrier frequencies and harmonically related low-frequency modulators. This finding was attributed to complex pitch perception requiring correct tonotopic representation but could have been due to the very high modulator rate difference limens (DLs) observed for individual transposed tones. Experiments 1 and 2 showed that much lower DLs could be obtained for bandpass-filtered pulse trains than for transposed tones with repetition rates of 100 or 300 pps; however, DLs were still larger than for low-frequency pure tones. Experiment 3 presented three pulse trains filtered between 1375 and 1875, 3900 and 5400, and 7800 and 10 800 Hz simultaneously with a pink-noise background. Listeners could not compare the "missing fundamental" of a stimulus in which the pulse rates were, respectively, 150, 225, and 300 pps, to one where all pulse trains had a rate of 75 pps, even though they could compare a 150 + 225 + 300 Hz complex tone to a 75-Hz pure tone. Hence although filtered pulse trains can produce fairly good pitch perception of simple stimuli having low repetition rates and high-frequency spectral content, no evidence that such stimuli enable complex pitch perception in the absence of a place-rate match was found.

Section: Introductionmentioning

confidence: 99%

Further examination of complex pitch perception in the absence of a place--rate match

Deeks

Gockel

Carlyon

2013

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“…Generally, the dominant region has been found to correspond to harmonics with low numbers, with ranks between 3 and 5 (Plomp, 1967;Ritsma, 1967), which are generally believed to be resolved in the peripheral auditory system (Plomp, 1964;Plomp and Mimpen, 1968;Moore and Gockel, 2011). However, it has been suggested that the dominant region is not fixed in terms of harmonic number, but corresponds to a fixed frequency region around 500 to 800 Hz (Terhardt et al, 1982;Dai, 2000).…”

Section: Introductionmentioning

confidence: 99%

The dominant region for the pitch of complex tones with low fundamental frequencies

Jackson

Moore

2013

The dominant region for pitch for complex tones with low fundamental frequency (F0) was investigated. Thresholds for detection of a change in F0 (F0DLs) were measured for a group of harmonics (group B) embedded in a group of fixed non-overlapping harmonics (group A) with the same mean F0. It was assumed that F0DLs would be smallest when the harmonics in group B fell in the dominant region. The rank of the lowest harmonic in group B, N, was varied from 1 to 15. When all components had the same level, F0DLs increased with increasing N, but the increase started at a lower value of N for F0 = 200 Hz than for F0 = 50 or 100 Hz, the opposite of what would be expected if the dominant region corresponds to resolved harmonics. When the component levels followed an equal-loudness contour, F0DLs for F0 = 50 Hz were lowest for N = 1, but overall performance was much worse than for equal-level components, suggesting that the lowest harmonics were masking information from the higher harmonics.

“…While the resolving power of the normal auditory system is still in debate, it is usually accepted that harmonics with numbers above eight are poorly, if at all, resolved (see Moore and Gockel, 2011 for a review). However, in the present study, and for speech recognition in noise in general, the notion of spectrally resolved harmonics is not directly relevant.…”

Section: B Contribution Of Resolved Harmonics To the Benefit From DCmentioning

confidence: 99%

Dual-carrier processing to convey temporal fine structure cues: Implications for cochlear implants

Apoux

Youngdahl

Yoho

et al. 2015

Speech intelligibility in noise can be degraded by using vocoder processing to alter the temporal fine structure (TFS). Here it is argued that this degradation is not attributable to the loss of speech information potentially present in the TFS. Instead it is proposed that the degradation results from the loss of sound-source segregation information when two or more carriers (i.e., TFS) are substituted with only one as a consequence of vocoder processing. To demonstrate this segregation role, vocoder processing involving two carriers, one for the target and one for the background, was implemented. Because this approach does not preserve the speech TFS, it may be assumed that any improvement in intelligibility can only be a consequence of the preserved carrier duality and associated segregation cues. Three experiments were conducted using this "dual-carrier" approach. All experiments showed substantial sentence intelligibility in noise improvements compared to traditional single-carrier conditions. In several conditions, the improvement was so substantial that intelligibility approximated that for unprocessed speech in noise. A foreseeable and potentially promising implication for the dual-carrier approach involves implementation into cochlear implant speech processors, where it may provide the TFS cues necessary to segregate speech from noise.