This is a Heroku buildpack for using sox in your project.
Shamelessly forked from the ffmpeg heroku buildpack by Shunji Konishi.
To use this buildpack, you should prepare a .buildpacks file that contains this buildpack url and your real buildpack url:
$ ls
.buildpacks
$ cat .buildpacks
https://github.com/RBNA/soundselect-sox-buildpack
You can verify that sox is installed by calling:
$ heroku run "sox"