# Sensitivity to Haptic-Audio Envelope Asynchrony

## TL;DR

This study investigates human perception of amplitude and timing differences between haptic and audio signals through four psychophysical experiments, revealing specific thresholds for detecting asynchrony and amplitude changes.

## Contribution

It provides new quantitative data on the just noticeable differences in haptic-audio envelope asynchrony and amplitude perception, advancing understanding in multisensory integration.

## Key findings

- JND for attack asynchrony is 54ms
- JND for decay asynchrony is 265ms
- Amplitude decrease JND is 25%

## Abstract

We want to understand the human capabilities to perceive amplitude similarities between a haptic and an audio signal. So, four psychophysical experiments were performed. Three of them measured the asynchrony JND (Just Noticeable Difference) at the signals' attack, release and decay, while the forth experiment measured the amplitude decrease on the middle of the signal. All the experiments used a combination of the constant stimulus and staircase methods to present two stimuli, while the participants' (N=12) task was to identify which of the two stimuli was synchronized. The audiotactile stimulus was defined using an stereo audio signal with an ADSR (Attack Decay Sustain Release) envelope. The partial results reveal JNDs for temporal asynchrony of: 54ms for attack, 265ms for decay and 57ms for release. Also the results reveal an amplitude decrease JND of 25\%. Although for decay the results were to disperse, therefore we suspect that the participants were not able to the changes on the haptic signal.

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Source: https://tomesphere.com/paper/1906.11571