Adaptively Matching Perceptual Duration of Flat and Percussive Tones

Abstract

The extensive literature on duration assessment generally uses tones with clear onsets and offsets.  However, simplistic sounds can fail to evoke the same processes used when listening to sounds with time varying amplitude envelopes (Schutz & Gillard, 2020). Researchers use simplistic sounds to control for extraneous variables between different sounds, with one of these being duration perception. To facilitate future research on the duration assessment of time varying tones, here we explore the ratio at which constant amplitude ‘flat’ and varying amplitude ‘percussive’ tones are perceived as the same duration. We used an adaptive staircase procedure, which presented flat and percussive tones in pairs; participants then stated which tone sounded longer in duration. Each response changed the duration difference on subsequent trials and continued until responses converged around a point, with convergence defined as four consecutive reversals in response direction. One instance of these trials constituted a single staircase; we then calculated the millisecond point of subjective equality (PSE) between flat and percussive tones by finding the average point of convergence between multiple, interleaved staircases starting above and below an initial duration. We found a ratio of flat to percussive duration of approximately 1.67, though with high variance. Consistent, low-variance results from a homogenous (same envelope comparisons) version of the experiment suggest that the adaptive procedure is not the cause. As a result, future iterations will involve collecting large amounts of data from a smaller sample in a controlled lab setting, thereby reducing individual differences and extraneous variables.