Speeding up Speech with mplayer

Mplayer is a fantastic media player and I have been using it as the default tool to play both music and speech for years now.

One of it’s lesser known features is the ability to speed up or slow down whatever it’s playing. Not very useful for music but very handy if you are listening to speech. In some cases you may wish to speed up podcasts, to get more enjoyment in. In other cases you may want to slow down a recording so that you can transcribe the text. For people with Dyslexia this is very empowering as it gives them control over the rate of input.

You can use the {, [, backspace, ], }, keys to control the speed.

• { key will slow down by 50% of the current rate
• [ key will slow down by 10% of the current rate
• Backspace will return the speed to normal
• ] key will speed up 10% of the current rate
• } key will speed up by 50% of the current rate
• 9 key will decrease the volume
• 0 key will increase the volume

I strongly recommend taking some time to review the keyboard controls in the manpage.

By default mplayer will not maintain pitch when you change the speed. So if you speed it up the speaker starts to sound like a chipmunk, and if you slow it down female voices start to sound like male voices.

You can change this by starting mplayer with the switch -af scaletempo

You can change this quickly by creating an alias

alias mplayer='mplayer -af scaletempo'

A more permanent way to set this is to configure your mplayer configuration file. Simply add the following in the “# audio settings #” section

af=scaletempo

See the Configuration Files section in the man page for more information.

The system-wide configuration file ‘mplayer.conf’ is in your configuration directory (e.g. /etc/mplayer or /usr/local/etc/mplayer), the user specific one is ~/.mplayer/config. User specific options override system-wide options and options given on the command line override either.