kdazzle’s solution is almost there – it still output a stereo wav, here is a slightly modified version that generate mono: ffmpeg -i 111.mp3 -acodec pcm_s16le -ac 1 -ar 16000 out.wav also, if this is for pre-processing speech data for sphinx 4 see here: Convert audio files for CMU Sphinx 4 input
Take a look at the -t and -ss arguments. They should do what you want. -t duration Restrict the transcoded/captured video sequence to the duration specified in seconds. hh:mm:ss[.xxx] syntax is also supported. -ss position’ Seek to given time position in seconds. hh:mm:ss[.xxx] syntax is also supported. For example, ffmpeg -ss 30 -t 70 -i … Read more
I also recommend ffmpeg, but the command line suggested by John Boker has an unintended side effect: it re-encodes the file to the default bitrate (which is 64 kb/s in the version I have here at least). This might give your customers a false impression of the quality of your sound files, and it also … Read more