How do I De-Ess a sound file with SoX?

Question

I am using SoX to create slow but pitch corrected audio files. The resulting files sound pretty good, but often have a very hard "S" sound that I would like to filter out. Many desktop programs include a "De-Essing" filter that works well, but I would like to have a filter that works on the server side. What SoX filter and parameters should I use to De-Ess an audio file? Edit: I should add that this needs to work on Linux.

Accepted Answer

There is a LADSPA DeEsser plugin that can be used from SoX. You need to have tap plugins installed and properly configured on your system. On Archlinux this can be easily achieved with

```
pacman -S tap-plugins
```

You can specify threshold and frequency as first and second arguments. I succesfully used a variant of the following command

```
# -30: threshold (dB)
# 6200: hiss frequency (Hz)
sox from.wav to.wav ladspa tap_deesser tap_deesser -30 6200
```

The filter has a fistful of other options I did not analyzed. More details can be found here.

How do I De-Ess a sound file with SoX?

Solution

Problem