etgld

ffmpeg -i input.mp3 -acodec pcm_s16le -ac 1 -ar 16000 output.wav

# To convert all mp3 files in a directory in Linux:

for f in *.mp3; do ffmpeg -i "$f" -acodec pcm_s16le -ac 1 -ar 16000 "${f%.mp3}.wav"; done

# Or Windows:

for /r %i in (*) do ffmpeg -i %i -acodec pcm_s16le -ac 1 -ar 16000 %i.wav