pcm.!default { type asym playback.pcm "eci" capture.pcm "eco" } pcm.eci { type plug slave { format S16_LE rate 16000 channels 1 pcm { type file slave.pcm null file "/tmp/ec.input" format "raw" } } } pcm.eco { type plug slave.pcm { type fifo infile "/tmp/ec.output" rate 16000 format S16_LE channels 2 } }