当我将耳机插入前面板插孔时，pavucontrol会检测它们（Output Devices > USB Audio Analog Stereo > Port: Headphones (plugged in)存在时与Port: Digital Output (S/PDIF)拔出时）。如果音频定向到此接收器，则pactl显示音频正在播放（通常的输出电平表亮起），但实际上耳机中没有声音。我已经确认耳机可以在其他地方使用，无论是在其他设备中还是在同一台计算机上的线路输出端口（遗憾的是，该计算机的位置不适合用于耳机）。
pactl list cards插入耳机时相关卡（好像都是主板内置音频，前后都有）的输出如下：
Card #2
Name: alsa_card.usb-Generic_USB_Audio-00
Driver: module-alsa-card.c
Owner Module: 8
Properties:
alsa.card = "3"
alsa.card_name = "USB Audio"
alsa.long_card_name = "Generic USB Audio at usb-0000:00:14.0-9, high speed"
alsa.driver_name = "snd_usb_audio"
device.bus_path = "pci-0000:00:14.0-usb-0:9:1.0"
sysfs.path = "/devices/pci0000:00/0000:00:14.0/usb1/1-9/1-9:1.0/sound/card3"
udev.id = "usb-Generic_USB_Audio-00"
device.bus = "usb"
device.vendor.id = "0414"
device.vendor.name = "Giga-Byte Technology Co., Ltd"
device.product.id = "a010"
device.product.name = "USB Audio"
device.serial = "Generic_USB_Audio"
device.string = "3"
device.description = "USB Audio"
module-udev-detect.discovered = "1"
device.icon_name = "audio-card-usb"
Profiles:
input:analog-stereo: Analog Stereo Input (sinks: 0, sources: 1, priority: 65, available: no)
input:iec958-stereo: Digital Stereo (IEC958) Input (sinks: 0, sources: 1, priority: 55, available: yes)
output:analog-stereo: Analog Stereo Output (sinks: 1, sources: 0, priority: 6500, available: yes)
output:analog-stereo+input:analog-stereo: Analog Stereo Duplex (sinks: 1, sources: 1, priority: 6565, available: no)
output:analog-stereo+input:iec958-stereo: Analog Stereo Output + Digital Stereo (IEC958) Input (sinks: 1, sources: 1, priority: 6555, available: yes)
output:analog-surround-21: Analog Surround 2.1 Output (sinks: 1, sources: 0, priority: 1300, available: no)
output:analog-surround-21+input:analog-stereo: Analog Surround 2.1 Output + Analog Stereo Input (sinks: 1, sources: 1, priority: 1365, available: no)
output:analog-surround-21+input:iec958-stereo: Analog Surround 2.1 Output + Digital Stereo (IEC958) Input (sinks: 1, sources: 1, priority: 1355, available: no)
output:analog-surround-40: Analog Surround 4.0 Output (sinks: 1, sources: 0, priority: 1200, available: no)
output:analog-surround-40+input:analog-stereo: Analog Surround 4.0 Output + Analog Stereo Input (sinks: 1, sources: 1, priority: 1265, available: no)
output:analog-surround-40+input:iec958-stereo: Analog Surround 4.0 Output + Digital Stereo (IEC958) Input (sinks: 1, sources: 1, priority: 1255, available: no)
output:analog-surround-41: Analog Surround 4.1 Output (sinks: 1, sources: 0, priority: 1300, available: no)
output:analog-surround-41+input:analog-stereo: Analog Surround 4.1 Output + Analog Stereo Input (sinks: 1, sources: 1, priority: 1365, available: no)
output:analog-surround-41+input:iec958-stereo: Analog Surround 4.1 Output + Digital Stereo (IEC958) Input (sinks: 1, sources: 1, priority: 1355, available: no)
output:analog-surround-50: Analog Surround 5.0 Output (sinks: 1, sources: 0, priority: 1200, available: no)
output:analog-surround-50+input:analog-stereo: Analog Surround 5.0 Output + Analog Stereo Input (sinks: 1, sources: 1, priority: 1265, available: no)
output:analog-surround-50+input:iec958-stereo: Analog Surround 5.0 Output + Digital Stereo (IEC958) Input (sinks: 1, sources: 1, priority: 1255, available: no)
output:analog-surround-51: Analog Surround 5.1 Output (sinks: 1, sources: 0, priority: 1300, available: no)
output:analog-surround-51+input:analog-stereo: Analog Surround 5.1 Output + Analog Stereo Input (sinks: 1, sources: 1, priority: 1365, available: no)
output:analog-surround-51+input:iec958-stereo: Analog Surround 5.1 Output + Digital Stereo (IEC958) Input (sinks: 1, sources: 1, priority: 1355, available: no)
output:analog-surround-71: Analog Surround 7.1 Output (sinks: 1, sources: 0, priority: 1200, available: no)
output:analog-surround-71+input:analog-stereo: Analog Surround 7.1 Output + Analog Stereo Input (sinks: 1, sources: 1, priority: 1265, available: no)
output:analog-surround-71+input:iec958-stereo: Analog Surround 7.1 Output + Digital Stereo (IEC958) Input (sinks: 1, sources: 1, priority: 1255, available: no)
output:iec958-stereo: Digital Stereo (IEC958) Output (sinks: 1, sources: 0, priority: 5500, available: yes)
output:iec958-stereo+input:analog-stereo: Digital Stereo (IEC958) Output + Analog Stereo Input (sinks: 1, sources: 1, priority: 5565, available: no)
output:iec958-stereo+input:iec958-stereo: Digital Stereo Duplex (IEC958) (sinks: 1, sources: 1, priority: 5555, available: yes)
off: Off (sinks: 0, sources: 0, priority: 0, available: yes)
Active Profile: output:analog-stereo
Ports:
analog-input-mic: Microphone (type: Mic, priority: 8700, latency offset: 0 usec, not available)
Properties:
device.icon_name = "audio-input-microphone"
Part of profile(s): input:analog-stereo, output:analog-stereo+input:analog-stereo, output:analog-surround-21+input:analog-stereo, output:analog-surround-40+input:analog-stereo, output:analog-surround-41+input:analog-stereo, output:analog-surround-50+input:analog-stereo, output:analog-surround-51+input:analog-stereo, output:analog-surround-71+input:analog-stereo, output:iec958-stereo+input:analog-stereo
analog-input-linein: Line In (type: Line, priority: 8100, latency offset: 0 usec, not available)
Part of profile(s): input:analog-stereo, output:analog-stereo+input:analog-stereo, output:analog-surround-21+input:analog-stereo, output:analog-surround-40+input:analog-stereo, output:analog-surround-41+input:analog-stereo, output:analog-surround-50+input:analog-stereo, output:analog-surround-51+input:analog-stereo, output:analog-surround-71+input:analog-stereo, output:iec958-stereo+input:analog-stereo
iec958-stereo-input: Digital Input (S/PDIF) (type: SPDIF, priority: 0, latency offset: 0 usec, availability unknown)
Part of profile(s): input:iec958-stereo, output:analog-stereo+input:iec958-stereo, output:analog-surround-21+input:iec958-stereo, output:analog-surround-40+input:iec958-stereo, output:analog-surround-41+input:iec958-stereo, output:analog-surround-50+input:iec958-stereo, output:analog-surround-51+input:iec958-stereo, output:analog-surround-71+input:iec958-stereo, output:iec958-stereo+input:iec958-stereo
analog-output-speaker: Speakers (type: Speaker, priority: 10000, latency offset: 0 usec, not available)
Properties:
device.icon_name = "audio-speakers"
Part of profile(s): output:analog-stereo, output:analog-stereo+input:analog-stereo, output:analog-stereo+input:iec958-stereo, output:analog-surround-21, output:analog-surround-21+input:analog-stereo, output:analog-surround-21+input:iec958-stereo, output:analog-surround-40, output:analog-surround-40+input:analog-stereo, output:analog-surround-40+input:iec958-stereo, output:analog-surround-41, output:analog-surround-41+input:analog-stereo, output:analog-surround-41+input:iec958-stereo, output:analog-surround-50, output:analog-surround-50+input:analog-stereo, output:analog-surround-50+input:iec958-stereo, output:analog-surround-51, output:analog-surround-51+input:analog-stereo, output:analog-surround-51+input:iec958-stereo, output:analog-surround-71, output:analog-surround-71+input:analog-stereo, output:analog-surround-71+input:iec958-stereo
analog-output-headphones: Headphones (type: Headphones, priority: 9900, latency offset: 0 usec, available)
Properties:
device.icon_name = "audio-headphones"
Part of profile(s): output:analog-stereo, output:analog-stereo+input:analog-stereo, output:analog-stereo+input:iec958-stereo
iec958-stereo-output: Digital Output (S/PDIF) (type: SPDIF, priority: 0, latency offset: 0 usec, availability unknown)
Part of profile(s): output:iec958-stereo, output:iec958-stereo+input:analog-stereo, output:iec958-stereo+input:iec958-stereo
拔掉耳机后，与上面的区别如下：
26c26
< output:analog-stereo: Analog Stereo Output (sinks: 1, sources: 0, priority: 6500, available: yes)
---
> output:analog-stereo: Analog Stereo Output (sinks: 1, sources: 0, priority: 6500, available: no)
28c28
< output:analog-stereo+input:iec958-stereo: Analog Stereo Output + Digital Stereo (IEC958) Input (sinks: 1, sources: 1, priority: 6555, available: yes)
---
> output:analog-stereo+input:iec958-stereo: Analog Stereo Output + Digital Stereo (IEC958) Input (sinks: 1, sources: 1, priority: 6555, available: no)
51c51
< Active Profile: output:analog-stereo
---
> Active Profile: output:iec958-stereo
65c65
< analog-output-headphones: Headphones (type: Headphones, priority: 9900, latency offset: 0 usec, available)
---
> analog-output-headphones: Headphones (type: Headphones, priority: 9900, latency offset: 0 usec, not available)
（卡 #0 是带 HDMI 输出的 GPU，卡 #1 是带麦克风的网络摄像头）
我在 Arch Linux 上。我已经检查过了alsamixer；任何卡上都没有静音。