Depends what you mean by audio programmer. I’m assuming you mean the person who actually implements all of the audio library code into the game engine. That, or actually implementing an audio engine itself. Definitely hard to find us programmers who know their way around that sort of stuff.
It seems to be for this reason that usually the choice is to be to go for a middleware package that keeps implementation easy, and doesn’t require much programming knowledge from the audio designer’s side.
But, yeah, if you want to go for the serious programmer side… You definitely will need to know C++, just scripting is not sufficient in this case. You’ll also need sufficient knowledge about things like FFT, resampling (linear, windowed sinc, etc), low pass filters, audio spatialization, the various implementations for reverb effects, some basic knowledge about audio compression, where to use compression and where to use raw samples, etcetera.
There definitely could be some interesting opportunities with AMD’s upcoming hardware accelerated programmable audio capabilities on their latest cards, as well. It could lead to a much more diverse and artistic pallette of audio effects than we currently have, similar to what graphics shaders did to the fixed graphics pipeline. Audio is currently still pretty much fixed pipeline for the most part.