These are the commands I use to verify if the sound card can record at 16KHz:
$ arecord -l **** List of CAPTURE Hardware Devices **** card 0: PCH [HDA Intel PCH], device 0: ALC275 Analog [ALC275 Analog] Subdevices: 1/1 Subdevice #0: subdevice #0 alan@aureo:~$ arecord -B 120000 -D "hw:CARD=0,DEV=0" -r 16000 -c 1 -f S16_LE file.wav -v Recording WAVE 'file.wav' : Signed 16 bit Little Endian, Rate 16000 Hz, Mono arecord: set_params:1087: Channels count non available $ arecord -B 120000 -D "hw:CARD=0,DEV=0" -r 16000 -c 2 -f S16_LE file_2ch.wav -v Recording WAVE 'file_2ch.wav' : Signed 16 bit Little Endian, Rate 16000 Hz, Stereo Warning: rate is not accurate (requested = 16000Hz, got = 44100Hz) please, try the plug plugin Hardware PCM card 0 'HDA Intel PCH' device 0 subdevice 0 Its setup is: stream : CAPTURE access : RW_INTERLEAVED format : S16_LE subformat : STD channels : 2 rate : 44100 exact rate : 44100 (44100/1) msbits : 16 buffer_size : 5292 period_size : 1323 period_time : 30000 tstamp_mode : NONE period_step : 1 avail_min : 1323 period_event : 0 start_threshold : 1 stop_threshold : 5292 silence_threshold: 0 silence_size : 0 boundary : 1387266048 appl_ptr : 0 hw_ptr : 0 ^C Aborted by signal Interrupt... $ mplayer file_2ch.wav MPlayer svn r34540 (Ubuntu), built with gcc-4.6 (C) 2000-2012 MPlayer Team mplayer: could not connect to socket mplayer: No such file or directory Failed to open LIRC support. You will not be able to use your remote control. Playing file_2ch.wav. libavformat version 53.21.0 (external) Mismatching header version 53.19.0 Audio only file format detected. Load subtitles in ./ ========================================================================== Opening audio decoder: [pcm] Uncompressed PCM audio decoder AUDIO: 44100 Hz, 2 ch, s16le, 1411.2 kbit/100.00% (ratio: 176400->176400) Selected audio codec: [pcm] afm: pcm (Uncompressed PCM) ========================================================================== AO: [pulse] 44100Hz 2ch s16le (2 bytes per sample) Video: no video Starting playback... A: 12.7 (12.7) of 13.0 (13.0) 0.1% (pressed Ctrl+C to finish recording) Exiting... (End of file)
In this case the sound card cannot manage audio record at 16KHz and changed it to 44100 Hz
Alan C. Assis 