Related Experiment Video
Updated: Jan 14, 2026
09:04
Uncovering Beat Deafness: Detecting Rhythm Disorders with Synchronized Finger Tapping and Perceptual Timing Tasks
Published on: March 16, 2015
13.3K
Not proportional after all: Investigating speed perception with the beep-speed illusion
Simon Merz1,2, Joanna Sommerfeld3, Christian Frings4,5
1Department of Psychology, Cognitive Psychology & Institute for Cognitive and Affective Neuroscience, University of Trier, Universitätsring 15, 54286, Trier, Germany. merzs@uni-trier.de.
Attention, Perception & Psychophysics
|January 12, 2026
Summary
The beep-speed illusion shows motion speed perception is altered by sound. This study found illusion size and speed estimation precision are not proportional to object speed, challenging traditional models.
Area of Science:
- Psychology
- Neuroscience
- Auditory Perception
Background:
- A novel audiovisual illusion, the beep-speed illusion, has been identified.
- This illusion affects the perceived speed of visually moving objects when paired with auditory stimuli.
Purpose of the Study:
- To investigate the representation of motion speed in human perception using the beep-speed illusion.
- To examine how audiovisual interactions influence speed perception across different object speeds and motion paths.
Main Methods:
- Two experiments were conducted with 30 participants each.
- The beep-speed illusion was tested using circular motion paths and varying audiovisual object speeds.
Main Results:
- The beep-speed illusion was successfully replicated with circular motion.
- The magnitude of the illusion and the precision of speed estimation (just noticeable difference) did not scale proportionally with object speed.
Conclusions:
- The findings challenge the classical Weber law's predictions regarding proportional speed estimation.
- Results suggest complex interactions in audiovisual motion perception that deviate from simple proportionality models.
Related Concept Videos
00:56Doppler Effect - I
6.0K
The Doppler effect and Doppler shift were named after the Austrian physicist and mathematician Christian Johann Doppler in 1842, who conducted experiments with both moving sources and moving observers. Consider an observer standing on a street corner, observing an ambulance with a siren sound passing by at a constant speed. The observer experiences two characteristic changes in the sound of the siren. Initially, the sound increases in loudness as the ambulance approaches and decreases in...
6.0K
01:05Doppler Effect - II
4.3K
The Doppler effect has several practical, real-world applications. For instance, meteorologists use Doppler radars to interpret weather events based on the Doppler effect. Typically, a transmitter emits radio waves at a specific frequency toward the sky from a weather station. The radio waves bounce off the clouds and precipitation and travel back to the weather station. The radio frequency of the waves reflected back to the station appears to decrease if the clouds or precipitation are moving...
4.3K