[pierrec]

Modern CPUs actually make decent general purpose DSPs for audio, so I'm not sure what kind of hardware acceleration you expect. Parallelization? Audio processing is not as extremely parallelizable as video. It's somewhat parallelizable. In a classic audio filter function, each sample affects the sample that comes immediately after it, so it's not embarrassingly parallel. The best you can do is, for example, parallelize multiple independent filters, so CPU SIMD instructions often turn out to be a decent fit.

As a side note, for some common audio DSP tasks, you could presumably take better advantage of highly parallel processing by doing a fourier transform and working in the spectral domain. There has been research do do this on GPUs and it works. However, if you do this you'll have high latency, and it's not a hardware problem, it's inherent to the FFT algorithm, so it's kind of a dead end for many applications.