Hi, there's no maintainer listed for the OpenAL package, so I'm posting here in hopes of finding the right person. The unqueueBuffers function in Sound.OpenAL.AL.Source has the type Source -> [Buffer] -> IO () but I think the type should be Source -> Int -> IO [Buffer] This wraps the function alSourceUnqueueBuffers which uses the array of buffers as an output argument. With the current implementation, it's impossible to get the list of buffers that were unqueued. This implementation works the way I expect: unqueueBuffers :: AL.Source -> Int -> IO [AL.Buffer] unqueueBuffers source nbuffers = allocaArray nbuffers $ \ptr -> do alSourceUnqueueBuffers source (fromIntegral nbuffers) ptr peekArray nbuffers ptr I just started using OpenAL, so I might be misunderstanding how this is supposed to work. Thanks, Alex Midgley