Where is the beat in that note? Effects of attack, duration, and frequency on the perceived timing of musical and quasi-musical sounds AbstractWhen coordinating physical actions with sounds, we synchronise our actions with the perceptual center (P-center) of the sound, understood as the specific moment at which the sound is perceived to occur. Using matched sets of real and artificial musical sounds as stimuli, we probed the influence of Attack (rise time), Duration, and Frequency (center frequency) on perceived P-center location and P-center variability. Two different methods to determine the P-centers were used:Clicks aligned in-phase with the target sounds via the method of adjustment, and tapping in synchrony with the target sounds. We found that attack and duration are primary cues for Pcenter location and P-center variability, and that the latter is a useful measure of P-center shape.Probability density distributions for each stimulus display a systematic pattern of P-center shapes ranging from narrow peaks close to the onset of sounds with a fast attack and short duration, to wider and flatter shapes indicating a range synchronization points for sounds with a slow attack and long duration. The results support the conception of P-centers as not simple time points, but "beat bins" with characteristic shapes, and the shapes and locations of these beat bins are dependent upon both the stimulus and the synchronization task. Public significance statementIn music and dance, as well as many other contexts, we coordinate our physical actions with sounds. Our research shows how the fine-grained details of a sound interact in our temporal perception of it. This has implications for a wide range of applications that involve timing, from rehearsing musical ensembles to the sonification of complex patterns of information.

In speech and music, the acoustic and perceptual onset(s) of a sound are usually not congruent with its perceived temporal location. Rather, these "P-centers" are heard some milliseconds after the acoustic onset, and a variety of techniques have been used in speech and music research to find them. Here we report on a comparative study that uses various forms of the method of adjustment (aligning a click or filtered noise in-phase or anti-phase to a repeated target sound), as well as tapping in synchrony with a repeated target sound. The advantages and disadvantages of each method and probe type are discussed, and then all methods are tested using a set of musical instrument sounds that systematically vary in terms of onset/rise time (fast vs. slow), duration (short vs. long), and center frequency (high vs. low). For each method, the dependent variables were (a) the mean Pcenter location found for each stimulus type, and (b) the variability of the mean P-center location found for each stimulus type. Interactions between methods and stimulus categories were also assessed. We show that (a) in-phase and anti-phase methods of adjustment produce nearly identical results, (b) tapping vs. click alignment can provide different yet useful information regarding P-center locations, (c) the method of adjustment is sensitive to different sounds in terms of variability while tapping is not, and (d) using filtered noise as an alignment probe yields consistently earlier probe-onset locations in comparison to using a click as a probe.

Musical expertise improves the precision of timing perception and performance – but is this expertise generic, or is it tied to the specific style(s) and genre(s) of one’s musical training? We asked expert musicians from three musical genres (folk, jazz, and EDM/hip-hop) to align click tracks and tap in synchrony with genre-specific and genre-neutral sound stimuli to determine the perceptual center (“P-center”) and variability (“beat bin”) for each group of experts. We had three stimulus categories – Organic, Electronic, and Neutral sounds – each of which had a 2 × 2 design of the acoustic factors Attack (fast/slow) and Duration (short/long). We found significant effects of Genre expertise, and a significant interaction for both P-center and P-center variability: folk and jazz musicians synchronize to sounds typical of folk and jazz in a different manner than the EDM/hip-hop producers. The results show that expertise in a specific musical genre affects our low-level perceptions of sounds as well as their affordance(s) for joint action/synchronization. The study provides new insights into the effects of active long-term musical enculturation and skill acquisition on basic sensorimotor synchronization and timing perception, shedding light on the important question of how nature and nurture intersect in the development of our perceptual systems.