Timbral Shepard-illusion reveals ambiguity and context sensitivity of brightness perception

Siedenburg, Kai

doi:10.1121/1.5022983

Cited by 12 publications

(16 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Biases in relative pitch could also account for the biases seen in basic pitch discrimination, on the assumption that the decision variable is a representation of relative pitch. The influence of coarse spectral changes on relative pitch is consistent with findings that humans extract melody-like representations from such changes (Cousineau et al, 2014; Graves et al, 2014; Graves et al, 2019; McDermott et al, 2008; Siedenburg, 2018).…”

Section: Discussionsupporting

confidence: 85%

Relative pitch representations and invariance to timbre

McPherson

McDermott

2022

Preprint

View full text Add to dashboard Cite

Information in speech and music is often conveyed through changes in fundamental frequency (f0), the perceptual correlate of which is known as "pitch". One challenge of extracting this information is that such sounds can also vary in their spectral content due to the filtering imposed by a vocal tract or instrument body. Pitch is envisioned as invariant to spectral shape, potentially providing a solution to this challenge, but the extent and nature of this invariance remain poorly understood. We examined the extent to which human pitch judgments are invariant to spectral differences between natural sounds. Listeners performed up/down and interval discrimination tasks with spoken vowels, instrument notes, or synthetic tones, synthesized to be either harmonic or inharmonic (lacking a well-defined f0). Listeners were worse at discriminating pitch across different vowel and instrument sounds compared to when vowels/instruments were the same, being biased by differences in the spectral centroids of the sounds being compared. However, there was no interaction between this effect and that of inharmonicity. In addition, this bias decreased when sounds were separated by short delays. This finding suggests that the representation of a sound's pitch is itself unbiased, but that pitch comparisons between sounds are influenced by changes in timbre, the effect of which weakens over time. Pitch representations thus appears to be relatively invariant to spectral shape. But relative pitch judgments are not, even when spectral shape variation is naturalistic, and when such judgments are based on representations of the f0.

show abstract

Section: Discussionsupporting

confidence: 85%

Relative pitch representations and invariance to timbre

McPherson

McDermott

2022

Preprint

View full text Add to dashboard Cite

show abstract

“…The SFS manipulation was combined with an SE manipulation that has been shown to yield circular brightness perception [45]. A global spectral envelope was defined as Gaussian distribution as a function of log-frequency with a mean three octaves above f 0 and a standard deviation of one octave.…”

Section: Stimulimentioning

confidence: 99%

“…University of Oldenburg. All experiments started with a screening task [45], comprising 40 SE trials with 2 st and 3 st shifts. The screening task was used to ensure that participants understood the task.…”

Section: Procedures and Designmentioning

confidence: 99%

A unitary model of auditory frequency change perception

Siedenburg

Graves

Pressnitzer

2022

Preprint

Self Cite

View full text Add to dashboard Cite

Changes in the frequency content of sounds over time are arguably the most basic form of information about the behavior of sound-emitting objects. In perceptual studies, such changes have mostly been investigated separately, as aspects of either pitch or timbre. Here, we propose a unitary account of “up” and “down” subjective judgments of frequency change, based on a model combining auditory correlates of acoustic cues in a sound-specific and listener-specific manner. To do so, we introduce a generalized version of so-called Shepard tones, allowing symmetric manipulations of spectral information on a fine scale, usually associated to pitch (spectral fine structure, SFS), and on a coarse scale, usually associated timbre (spectral envelope, SE). In a series of behavioral experiments, listeners reported “up” or “down” shifts across pairs of generalized Shepard tones that differed in SFS, in SE, or in both. We observed the classic properties of Shepard tones for either SFS or SE shifts: subjective judgements followed the smallest log-frequency change direction, with cases of ambiguity and circularity. Interestingly, when both SFS and SE changes were applied concurrently (synergistically or antagonistically), we observed a trade-off between cues. Listeners were encouraged to report when they perceived “both” directions of change concurrently, but this rarely happened, suggesting a unitary percept. A computational model could accurately fit the behavioral data by combining different cues reflecting frequency changes after auditory filtering. The model revealed that cue weighting depended on the nature of the sound. When presented with harmonic sounds, listeners put more weight on SFS-related cues, whereas inharmonic sounds led to more weight on SE-related cues. Moreover, these stimulus-based factors were modulated by inter-individual differences, revealing variability across listeners in the detailed recipe for “up” and “down” judgments. We argue that frequency changes are tracked perceptually via the adaptive combination of a diverse set of cues, in a manner that is in fact similar to the derivation of other basic auditory dimensions such as spatial location.

show abstract

“…Third, there are many additional bistable and multistable paradigms to consider modeling [6,33,34,[112][113][114][115][116][117]. A first step towards handling these paradigms could be to extend the features included in the Central analysis to spectral-temporal features.…”

Section: Future Workmentioning

confidence: 99%

Ensemble modeling of auditory streaming reveals potential sources of bistability across the perceptual hierarchy

2020

View full text Add to dashboard Cite

Perceptual bistability-the spontaneous, irregular fluctuation of perception between two interpretations of a stimulus-occurs when observing a large variety of ambiguous stimulus configurations. This phenomenon has the potential to serve as a tool for, among other things, understanding how function varies across individuals due to the large individual differences that manifest during perceptual bistability. Yet it remains difficult to interpret the functional processes at work, without knowing where bistability arises during perception. In this study we explore the hypothesis that bistability originates from multiple sources distributed across the perceptual hierarchy. We develop a hierarchical model of auditory processing comprised of three distinct levels: a Peripheral, tonotopic analysis, a Central analysis computing features found more centrally in the auditory system, and an Object analysis, where sounds are segmented into different streams. We model bistable perception within this system by applying adaptation, inhibition and noise into one or all of the three levels of the hierarchy. We evaluate a large ensemble of variations of this hierarchical model, where each model has a different configuration of adaptation, inhibition and noise. This approach avoids the assumption that a single configuration must be invoked to explain the data. Each model is evaluated based on its ability to replicate two hallmarks of bistability during auditory streaming: the selectivity of bistability to specific stimulus configurations, and the characteristic log-normal pattern of perceptual switches. Consistent with a distributed origin, a broad range of model parameters across this hierarchy lead to a plausible form of perceptual bistability.

show abstract

Timbral Shepard-illusion reveals ambiguity and context sensitivity of brightness perception

Cited by 12 publications

References 17 publications

Relative pitch representations and invariance to timbre

Relative pitch representations and invariance to timbre

A unitary model of auditory frequency change perception

Ensemble modeling of auditory streaming reveals potential sources of bistability across the perceptual hierarchy

Contact Info

Product

Resources

About