The Franssen effect is an auditory illusion where the listener incorrectly localizes a sound.
The left speaker suddenly begins to produce a sharp pure tone.
The left one is decreased exponentially, and the right speaker becomes the main source of the sound.
At the beginning of the presentation, loudspeaker 1 emits a pure tone with a steep attacking slope.
This mislocalization remains, even if the test supervisor plugs off the cables of loudspeaker 1 demonstratively.