Comment 28 for bug 1246929

http://bazaar.launchpad.net/~ubuntu-branches/ubuntu/saucy/qemu-kvm/saucy/view/head:/audio/noaudio.c

specify none is selectIng noaudio (timer based audio emulation)

struct audio_driver no_audio_driver = {
    .name = "none",
    .descr = "Timer based audio emulation",
    .options = NULL,
    .init = no_audio_init,
    .fini = no_audio_fini,
    .pcm_ops = &no_pcm_ops,
    .can_be_default = 1,
    .max_voices_out = INT_MAX,
    .max_voices_in = INT_MAX,
    .voice_size_out = sizeof (NoVoiceOut),
    .voice_size_in = sizeof (NoVoiceIn)
};