asloane wrote:I need to convert lectures from their original 16-bit WAV and 320 kbps MP3 format down to 96kbps MP3's for audio streaming.
You will get much a better sounding MP3 if the recording is mono rather than stereo. If you have a stereo track, convert it to mono before exporting.
If you use Audacity 1.3.x you also have the option to export as Variable Bit Rate (VBR) MP3, which will generally give slightly better sound quality than Constant Bit Rate (CBR). The downside to VBR is that some MP3 players will incorrectly report the length/playing time (though almost all MP3 players these days will play VBR OK).
For speech you may find that it sounds less bubbly if you filter the recording before encoding - (very easy to do in Audacity 1.3.x). For intelligibility, speech is almost all in the frequency range of 300Hz to 3kHz. If you use a 12dB/octave High-pass filter set to about 150Hz, and then use a 12dB/octave Low-pass filter set to about 8kHz (10000Hz) you will probably find that it sounds pretty good right down to 64kbps CBR (mono).