A command to change the spectral slope of every selected Sound object.

The reverse of Sound: Pre-emphasize (in-place).... For an example, see Source-filter synthesis.

This is the in-place version of Sound: Filter (de-emphasis)..., i.e., it does not create a new Sound object but modifies an existing object.

Setting

From frequency (Hz)

the frequency F above which the spectral slope will decrease by 6 dB/octave.

Algorithm

The de-emphasis factor l is computed as

where Δt is the sampling period of the sound. Every sample x_i of the sound, except x₁, is then changed, going up from the second sample:

Links to this page

• Filtering