我刚刚从 Ubuntu 20.04 升级到 21.04。升级后，我无法将任何声音输出到 USB 耳机。耳机上的麦克风可以正常工作。输出到内置扬声器或耳机插孔也可以正常工作。
这在 Ubuntu 20.04 上运行良好。
在“声音”设置中，如果我尝试测试耳机，则不会显示任何扬声器。我测试的两款 USB 耳机（Sennheiser PC 8 和 Plantronics 5200）都出现这种情况
据我所知，音频实现已从 Pulseaudio 更改为 Pipewire。我通过 Google 找到的所有内容仍然指 Pulseaudio。所以我有点迷茫。
如能得到有关如何调试此问题的任何建议，我们将不胜感激。
更新：
pactl 列表卡
显示耳机。我认为这看起来不错……但我不是专家。
Card #71
Name: alsa_card.usb-Sennheiser_Communications_Sennheiser_USB_headset-00
Driver: alsa
Owner Module: n/a
Properties:
device.enum.api = "udev"
device.api = "alsa"
media.class = "Audio/Device"
api.alsa.path = "hw:1"
api.alsa.card = "1"
api.alsa.card.name = "Sennheiser USB headset"
api.alsa.card.longname = "Sennheiser Communications Sennheiser USB headset at usb-0000:00:14.0-2, full sp"
device.plugged.usec = "998216405"
device.bus_path = "pci-0000:00:14.0-usb-0:2:1.0"
device.sysfs.path = "/sys/devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:1.0/sound/card1"
device.bus-id = "usb-Sennheiser_Communications_Sennheiser_USB_headset-00"
device.bus = "usb"
device.subsystem = "sound"
device.vendor.id = "5013"
device.vendor.name = "Sennheiser Communications"
device.product.id = "37"
device.product.name = "Headset [PC 8]"
device.serial = "Sennheiser_Communications_Sennheiser_USB_headset"
device.form_factor = "headset"
device.name = "alsa_card.usb-Sennheiser_Communications_Sennheiser_USB_headset-00"
device.description = "Headset [PC 8]"
device.nick = "Sennheiser USB headset"
device.icon_name = "audio-headset-usb"
api.alsa.use-acp = "true"
api.acp.auto-profile = "false"
api.acp.auto-port = "false"
api.dbus.ReserveDevice1 = "Audio1"
factory.id = "14"
client.id = "31"
object.id = "71"
object.path = "alsa:pcm:1"
alsa.card = "1"
alsa.card_name = "Sennheiser USB headset"
alsa.long_card_name = "Sennheiser Communications Sennheiser USB headset at usb-0000:00:14.0-2, full sp"
alsa.driver_name = "snd_usb_audio"
device.string = "1"
Profiles:
off: Off (sinks: 0, sources: 0, priority: 0, available: yes)
output:analog-stereo+input:mono-fallback: Analog Stereo Output + Mono Input (sinks: 1, sources: 1, priority: 6501, available: yes)
output:analog-stereo: Analog Stereo Output (sinks: 1, sources: 0, priority: 6500, available: yes)
pro-audio: Pro Audio (sinks: 1, sources: 1, priority: 1, available: yes)
input:mono-fallback: Mono Input (sinks: 0, sources: 1, priority: 1, available: yes)
Active Profile: output:analog-stereo+input:mono-fallback
Ports:
analog-input-mic: Microphone (type: Mic, priority: 8700, latency offset: 0 usec, availability unknown)
Properties:
port.type = "mic"
device.icon_name = "audio-input-microphone"
card.profile.port = "0"
Part of profile(s): input:mono-fallback, output:analog-stereo+input:mono-fallback
analog-output-headphones: Headphones (type: Headphones, priority: 9900, latency offset: 0 usec, availability unknown)
Properties:
port.type = "headphones"
device.icon_name = "audio-headphones"
card.profile.port = "1"
Part of profile(s): output:analog-stereo, output:analog-stereo+input:mono-fallback
但是，pactl list sinks short没有显示出来，只有内置扬声器在工作：
43 alsa_output.pci-0000_00_1f.3.analog-stereo PipeWire s32le 2ch 48000Hz SUSPENDED
继续研究，我最终发现问题在于journalctl --user -u pipewire：
Aug 02 10:46:32 backxp-HP-EliteBook-840-G5 pipewire[2007]: ALSA lib confmisc.c:1281:(snd_func_refer) Unable to find definition 'cards.USB-Audio.pcm.front.0:CARD=1'
Aug 02 10:46:32 backxp-HP-EliteBook-840-G5 pipewire[2007]: ALSA lib conf.c:4745:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
Aug 02 10:46:32 backxp-HP-EliteBook-840-G5 pipewire[2007]: ALSA lib conf.c:5233:(snd_config_expand) Evaluate error: No such file or directory
Aug 02 10:46:32 backxp-HP-EliteBook-840-G5 pipewire[2007]: ALSA lib pcm.c:2660:(snd_pcm_open_noupdate) Unknown PCM front:1
Aug 02 10:46:32 backxp-HP-EliteBook-840-G5 pipewire[2007]: 'front:1': playback open failed: No such file or directory
Aug 02 10:46:32 backxp-HP-EliteBook-840-G5 pipewire[2007]: adapter 0x55c2e968c8b0: can't get format: No such file or directory
Aug 02 10:46:32 backxp-HP-EliteBook-840-G5 pipewire[2007]: usage: node.name=<string>
这让我看到了以下错误报告： https://gitlab.freedesktop.org/pipewire/pipewire/-/issues/332
我有 pipewire 0.3.32，所以我不明白为什么这不能解决我的问题。
答案1
在我的问题末尾提到的错误得到正确解决之前，我的问题的正确答案（和解决方法）似乎是手动重新启动所有与 Pipewire 相关的服务：
systemctl --user restart pipewire-media-session pipewire-pulse pipewire
更新：我已为此提交了一个新的 Pipewire 问题，因为我似乎无法重新打开前一个问题：https://gitlab.freedesktop.org/pipewire/pipewire/-/issues/1478