Numerical value biases sound localization

Abstract

Speech recognition starts with representations of basic acoustic perceptual features and ends by categorizing the sound based on long-term memory for word meaning. However, little is known about whether the reverse pattern of lexical influences on basic perception can occur. We tested for a lexical influence on auditory spatial perception by having subjects make spatial judgments of number stimuli. Four experiments used pointing or left/right 2-alternative forced choice tasks to examine perceptual judgments of sound location as a function of digit magnitude (1–9). The main finding was that for stimuli presented near the median plane there was a linear left-to-right bias for localizing smaller-to-larger numbers. At lateral locations there was a central-eccentric location bias in the pointing task, and either a bias restricted to the smaller numbers (left side) or no significant number bias (right side). Prior number location also biased subsequent number judgments towards the opposite side. Findings support a lexical influence on auditory spatial perception, with a linear mapping near midline and more complex relations at lateral locations. Results may reflect coding of dedicated spatial channels, with two representing lateral positions in each hemispace, and the midline area represented by either their overlap or a separate third channel.

Sensorimotor Integration Can Enhance Auditory Perception

“…The subtle nature shows that the comparison of expected and actual sensory feedback in motor control does not substantially distort perception. As with other influences on auditory perception such as spatial biases by eye position 43 , choice of effectors 44 , and numerosity 45 . The perceptual benefits of actively producing the sound are comparable to the magnitude of just-noticeable-differences.…”

Numbers in short-term memory bias auditory spatial perception.

“…Sixteen young adult participants were tested in a sound booth (age 19.2 ± 1.9; M/F = 7/9; 16/16 right-handed). In prior work we examined spatial judgments when participants listened to individual digits (Golob, Lewald, et al, 2017) and found that the correlations between digit magnitude and the measure of spatial hearing used below were r = .93 (Experiment 2) and r = .54 (Experiment 3, no cue condition). Power analysis showed that either six or 25 participants would be needed for power = .80, p < .05, depending on whether the larger or smaller correlation was used as the expected effect size.…”

“…Target locations varied between ±12° to the left or right of midline, and a sigmoidal-shaped function is apparent when target location is plotted against the proportion of trials having a “right” side judgment. The point of subjective equality (PSE) is defined as the location were left/right judgments were equally likely, and was predicted to vary with number magnitude as when directly making left/right judgments of number stimuli (Golob, Lewald, et al, 2017). Smaller numbers were expected to expand the left side of perceived space and move the PSE to the right, and the opposite pattern was expected for larger numbers.…”

“…By convention, negative degree values are locations to the left of midline and positive values are to the right of midline. The virtual locations were chosen based on a previous study (Golob, Lewald, et al, 2017). There is substantial variability within and between individuals in spatial hearing (Blauert, 1997), but impressions of the participants as well as the behavioral data indicate that the sounds were perceived at the intended locations.…”

“…Data were measured and entered into a spreadsheet during data collection. Based on our previous findings when judging number stimuli, we used analysis of variance (ANOVA) tests with a factor of location (9) and a linear contrast of PSE as a function of number magnitude (Golob, Lewald, et al, 2017). For clarity, the original degrees of freedom values are given in the results, however Greenhouse-Geisser corrections were performed when appropriate.…”