ffmpeg -i E:\ss\10m-bwl.mp3 -acodec pcm_s16le -f s16le -ac 1 -ar 16000 E:\ss\10m-bwl.pcm
ffmpeg -i E:\ss\20m-bwl.mp3 -acodec pcm_s16le -f s16le -ac 1 -ar 16000 E:\ss\20m-bwl.pcm
ffmpeg -i E:\ss\21m-ll.mp3 -acodec pcm_s16le -f s16le -ac 1 -ar 16000 E:\ss\21m-ll.pcm
ffmpeg -i E:\ss\25m-wl.mp3 -acodec pcm_s16le -f s16le -ac 1 -ar 16000 E:\ss\25m-wl.pcm