Does fundamental-frequency discrimination measure virtual pitch discrimination?

Abstract

Studies of pitch perception often involve measuring difference limens for complex tones ͑DLCs͒ that differ in fundamental frequency ͑F0͒. These measures are thought to reflect F0 discrimination and to provide an indirect measure of subjective pitch strength. However, in many situations discrimination may be based on cues other than the pitch or the F0, such as differences in the frequencies of individual components or timbre ͑brightness͒. Here, DLCs were measured for harmonic and inharmonic tones under various conditions, including a randomized or fixed lowest harmonic number, with and without feedback. The inharmonic tones were produced by shifting the frequencies of all harmonics upwards by 6.25%, 12.5%, or 25% of F0. It was hypothesized that, if DLCs reflect residue-pitch discrimination, these frequency-shifted tones, which produced a weaker and more ambiguous pitch than would yield larger DLCs than the harmonic tones. However, if DLCs reflect comparisons of component pitches, or timbre, they should not be systematically influenced by frequency shifting. The results showed larger DLCs and more scattered pitch matches for inharmonic than for harmonic complexes, confirming that the inharmonic tones produced a less consistent pitch than the harmonic tones, and consistent with the idea that DLCs reflect F0 pitch discrimination.

Complex pitch perception mechanisms are shared by humans and a New World monkey

“…Importantly, sensitivity to individual components would not necessarily require them to be in a harmonic relationship. A series of experiments that measured the change in F0DLs for inharmonic versus harmonic sounds found, where both groups had the same average resolvability and spectral range, that F0DLs were higher under the inharmonic condition (21,31,32). These results have been taken as evidence of a role of harmonicity in lowering F0DLs and, because F0DL for RESs is affected by changes to the fidelity of harmonicity, suggest that F0DL reflects sensitivity to a globally assembled pitch.…”

“…3A illustrates these spectral shifts. Generally, any inharmonic shift should produce a more ambiguous pitch compared with the harmonic condition (21). Fig.…”

“…Although each of these mechanisms alone is sufficient to evoke pitch, the relative strengths of the perceived pitch based on these mechanisms are different. Pitch strength (a measure of the salience of the perceived pitch) is commonly believed to be correlated with the ability to discriminate changes in F0 (21). The smallest change in F0 that a subject can discriminate, measured as the F0 difference limen (F0DL), is thought to be inversely related to pitch strength.…”

On the possibility of a place code for the low pitch of high-frequency complex tones

“…Such a correction was applied so that the audibility of the complex tones was approximately the same in all tested spectral regions. 3 In order to evaluate pitch salience, discrimination thresholds for equal frequency shifts of all stimulus components were predicted from the pitch matches, using an approach based on estimation theory (Edgeworth, 1908) and described in Micheyl et al (2010). The d 0 values predicted by this procedure can be used as an estimate of pitch salience.…”

A general formula for computing maximum proportion correct scores in various psychophysical paradigms with arbitrary probability distributions of stimulus observations

“…Yet another example of situations in which the Gaussian assumption is inadequate relates to experiments in which a stimulus feature, which could provide an unwanted cue for task performance, is randomly perturbed (or "roved") across observation intervals within a trial, or across trials, in order to limit its use by participants. Examples of this abound in both the auditory-perception literature (e.g., Berg & Green, 1990;Berliner & Durlach, 1973;Dai, 1994Dai, , 2008Dai & Green, 1993;Dai, Nguyen, & Green, 1995Hall & Fernandes, 1983;Henning, 1966;Jesteadt & Bilger, 1974;Kidd, Mason, Brantley, & Owen, 1989;Kidd, Mason, Uchanski, Brantley, & Shah, 1991;Micheyl, Divis, Wrobleski, & Oxenham, 2010;Moore & Glasberg, 1989;Oxenham & Buus, 2000;Semal & Demany, 2006;Spiegel, Picardi, & Green, 1981;Strickland & Dhar, 2000) and the visual-perception literature (e.g., Danilova & Mollon, 2010;Dannemiller & Stephens, 1998;Morgan, 2005;Nachmias, 1999Nachmias, , 2002Regan & Hamstra, 1991, 1992Webster, De Valois, & Switkes, 1990). In such "roving" experiments, the experimenter must determine the size of the roving range necessary to ensure that the highest Pc that participants can achieve using the unwanted cue is below a predefined target (e.g., 60 % correct).…”