Prepare .wav files
Different aligners may have different requirements for audio input. Most work well with 16 KHz, 16-bit precision, and mono channel, so it would be safe to format all the target .wav
files like that.
1.1 Praat
You can reformat your .wav
files in Praat using its interactive graphical interface. To acquire a single channel, select the sound > Convert > Convert to mono
or Extract one channel
; to change the sampling rate, select the sound > Convert > Resample
; then save it as a new .wav
. The default is 16-bit in Praat.
1.2 SoX
Alternatively, you can also use SoX
(Sound eXchange) commands in the Terminal. SoX is a collection of handy sound processing utilities. It is also required by P2FA. You can download it
here. To reformat the input.wav, we can use the following command in the Terminal having installed SoX.
$ sox input.wav -r 16k -b 16 -c 1 output.wav
The $
isn’t part of the command. It indicates that this is a Shell script in the Terminal. The flags here: -r
, -b
, -c
define the sampling rate, precision, and number of channel of the output.wav respectively.