usually the neomedia implementation opens the portaudio streams
with a sample rate (number of frames) of 8000. This is ok for our usage.
During read and write of data the code does not use this sample
rate but resamples the data. According to portaudio documentation
this does not give the best performance.
Quote from Pa_ReadStream documentation:
"frames: The number of frames to be read into buffer. This parameter
is not constrained to a specific range, however high performance
applications will want to match this parameter to the framesPerBuffer
parameter used when opening the stream."
Pa_WriteStream has a similar statement for its "frames" parameter.