The playheads

The playheads move through the entire sound file at different speeds.

They allow you to experiment with transpositions by varying the direction and playback speed^[1].

Their temporal shifts can generate different acoustic effects such as delay^[2] and phasing.

Sommaire

Références

Playback speed variation
Transposition
The principle of speed variation is to go through a recorded sound at a different speed than the one at which the recording was made. This then allows the exploration of the sound.
The variation of speed results in two simultaneous and correlated effects on the sound:
- The transposition of its pitch
- The deceleration or acceleration of time
Other less obvious changes will appear:
- Increment or reduction of the reverberation in the sound
- The sharpening or softening of the sound's attack
In spite of its often caricatural aspect, this modification is extremely powerful.
In extreme cases (very slow speed for example) it completely distorts the original sound and thus generates new "unheard of" material.
Reducing or increasing the playback speed by half or double means, in musical terms, to raise or lower the pitch by an octave.
Exemples:
Guy Reibel, Variations en étoile (1e variation) [audio]
Delay
The principle of delay is to repeat a sound with a variable time shift from its first emission.
If the delay is very small (less than 50 milliseconds), it is not perceived as a repetition but as a modification of the space around a sound.
In a stereophonic system, introducing a delay between the two channels suggests a displacement of the sound between the two speakers. Small delays generally bring a color of the sound and an enrichment of its timbre.
Beyond 50 milliseconds, the first emission and its repetition are perceived as two distinct sound phenomena.
Example:
Pierre Henry, Prisme 5e mouvement [audio]