Nat*_*ate 5 sound microphone 11.10
我的麦克风插孔中插入了音频输入。在 中alsamixer，当我取消静音并放大mic输入时，我可以从扬声器中听到此音频。但是，运行arecord -d 5 foo.wav并aplay foo.wav导致一个空文件；通过大胆录制时相同 - 空。
为什么会发生这种情况？如何记录此输入？
arecord -L 产生以下内容，如果这有帮助的话：
default
Playback/recording through the PulseAudio sound server
pulse
Playback/recording through the PulseAudio sound server
front:CARD=nForce2,DEV=0
NVidia nForce2, NVidia nForce2
Front speakers
surround40:CARD=nForce2,DEV=0
NVidia nForce2, NVidia nForce2
4.0 Surround output to Front and Rear speakers
surround41:CARD=nForce2,DEV=0
NVidia nForce2, NVidia nForce2
4.1 Surround output to Front, Rear and Subwoofer speakers
surround50:CARD=nForce2,DEV=0
NVidia nForce2, NVidia nForce2
5.0 Surround output to Front, Center and Rear speakers
surround51:CARD=nForce2,DEV=0
NVidia nForce2, NVidia nForce2
5.1 Surround output to Front, Center, Rear and Subwoofer speakers
surround71:CARD=nForce2,DEV=0
NVidia nForce2, NVidia nForce2
7.1 Surround output to Front, Center, Side, Rear and Woofer speakers
dmix:CARD=nForce2,DEV=0
NVidia nForce2, NVidia nForce2
Direct sample mixing device
dmix:CARD=nForce2,DEV=1
NVidia nForce2, NVidia nForce2 - MIC ADC
Direct sample mixing device
dsnoop:CARD=nForce2,DEV=0
NVidia nForce2, NVidia nForce2
Direct sample snooping device
dsnoop:CARD=nForce2,DEV=1
NVidia nForce2, NVidia nForce2 - MIC ADC
Direct sample snooping device
hw:CARD=nForce2,DEV=0
NVidia nForce2, NVidia nForce2
Direct hardware device without any conversions
hw:CARD=nForce2,DEV=1
NVidia nForce2, NVidia nForce2 - MIC ADC
Direct hardware device without any conversions
plughw:CARD=nForce2,DEV=0
NVidia nForce2, NVidia nForce2
Hardware device with all software conversions
plughw:CARD=nForce2,DEV=1
NVidia nForce2, NVidia nForce2 - MIC ADC
Hardware device with all software conversions
Input在System Settings -> Sound对话框选项卡上所做的更改根本没有区别。因为它们，我的扬声器没有声音，而且 Audacity 由于更改任何设置（连接器或输入音量）而没有记录任何内容。只有一种“声音输入设备” - Internal Audio Analog Stereo.
奇怪的是，在 Audacity 中，更改录音源（例如从default:Line:0到default:Mic:0，甚至Mono到Stereo）会设置mute上述对话框中的复选框。