If you got problem with /dev/dsp for CWIRC on Ubuntu, try to launch X-Chat by typing padsp xchat on terminal. this is pulseaudio problem. Latest Ubuntu are using pulseaudio, not alsa.
/dev/dsp CWIRC Problem On Ubuntu
By9M2PJU
Mar 24, 2011
By 9M2PJU
An amateur radio operator, military veteran, jack of all trades and master of none.
/dev/dsp is OSS not alsa, programs using alsa should be compatible with pulseaudio
Even with pulseaudio, you have something else driving the sound. If you removed all sound applications except pulseaudio, you will have no sound at all. pa is just an audio server. Without alsa or oss, you have no sound.