Ices volume

I’m using the ices command to stream a conference to an icecast server. This is working nicely, for the most part, but the volume is very low. The streamed ogg vorbis audio is much quieter than what I hear in a SIP client, for example (on the same machine with the same audio hardware, of course).

I’m using the debian package of asterisk, version 1.2.13~dfsg-2

Any idea what could be happening here? My one guess, which is probably far off the mark, would be that asterisk is outputting the mu-law audio, and ices is expecting plain 16bit pcm. If I’m following the conversion process properly, that could result in the volume reduction I’m seeing, but I’m not sure. ‘show channel ___’ shows the NativeFormat, ReadFormat and WriteFormat all as 64 for the ices channel though (and all the other channels…), which I gather is supposed to be linear PCM, so maybe I’m completely wrong.

Is there any way that I could boost the volume just for the audio going to ices? I don’t want to raise the volume for the conference as a whole if possible, since that’s sounding just fine for those talking.