SoX on OS X
Downloading SoX
You can find binaries and installers for SoX on its sourceforge downloads page
The current version the last time this page was updated was 14.4.1.
Download sox-14.4.1-macosx.zip from the Sourceforge page, unzip it, and put the unzipped folder somewhere where it'll stay permanently (like /Applications).
Adding SoX to your path
In the Terminal application, go to your home directory and list all of the files in it.
cd ~
ls -a
Look towards the top of the list for a file called .bash_profile. [1]
If there isn't one, you can create it by typing
touch .bash_profile
Open the file:
open .bash_profile
Add the following line to the end of the file.
export PATH=$PATH:/Applications/sox-14.4.1
If you put the SoX folder in a directory other than /Applications, change this line accordingly.
Save and close .bash_profile
[1] Note: You may instead find a .bash_login file. If you already have a .bash_login but NOT a .bash_profile, you can add the sox path to .bash_login instead. However, if in future you create a .bash_profile it will take precedence, so anything in .bash_login will be ignored. For this reason you should probably just use .bash_profile.
Checking for success
Close and reopen the Terminal window. Type in
which sox
The Terminal should print back
Applications/sox-14.4.1/sox