Actually it's the other way around, PulseAudio interferes with ALSA. Some common workarounds:
1. Use padsp: padsp ./survivor-bin
2. Disable pulseaudio entirely
3. Remove lib32/libasound.so.2. Your system must have a compatible libasound.so.2 installed
No matter the fix I use, I have a problem where playing for a few missions ends up cutting out some, and eventually all of the sound, like there's some kind of buffer that is filling up and running out of space eventually.
Restarting SG fixes it temporarily at least!
Yeah that code is horrible and buggy. Mac doesn't have FMOD so I ported OpenAL code from Trine to Shadowgrounds. Worked fine except the music was sometimes choppy because sound update was not being called often enough. On Trine this had been fixed properly but it required things like background loading of files which was too invasive change for Shadowgrounds.
So I fixed it by moving sound decoding and playing to a separate thread. Most computers are at least dual core, OpenAL documentation says this is OK and it works fine on Linux. Problem solved, right?
Wrong. Mac threw a fit. No matter what we did the Mac version would always crash very shortly. And I couldn't find the bug on Linux no matter what. So in the end I moved the entire sound system to a separate thread. This at least made Mac stop crashing but unfortunately there's still a bug somewhere. For some reason OpenAL sound sources are not properly cleaned up which eventually makes sound stop working. At this point we'd spent several weeks on this, deadline was looming and frustration was high. So our options were 1) accept choppy music playback, 2) accept crashing on Mac or 3) accept occasional need to restart the game when the sounds bug out. Number three was chosen as the least bad option.
tl;dr: Blame Macs shitty OpenAL implementation for any sound bugs.
When FB releases the Linux source for SG I'll go back and get the working OpenAL code from our internal Subversion and post that. That'll allow you to get better sound playback if you don't care about Macs.