ffmpeg -i 01.chs.mp4 -metadata encoder="Lavf58.45.100" -t 60 -acodec pcm_s16le -ar 16000 -ac 1 -b:a 256k 01.chs.60s.wav

ffmpeg -i 01.chs.mp4 -metadata encoder="Lavf58.45.100" -ss 00:00:6.903 -to 00:00:13.648 -acodec pcm_s16le -ar 16000 -ac 1 -b:a 256k 01.chs.ssto.wav