No sound with pidgin, etc. on kubuntu

Problem: error message

play soxio: Failed reading `test.wav': unknown file type `auto'

Solution:

$ sudo apt-get install libsox-fmt-base libsox-fmt-ao

Installs everything you need just for the wave (.wav) format, *or use *

$ sudo apt-get install libsox-fmt-all

to install all available formats for sox and the play command.