我使用的是 ubuntu 13.10 64bit。我的耳机里只有单声道的声音。笔记本电脑扬声器很好。笔记本电脑的耳机插孔和耳机都工作正常。这是软件问题。我定期升级系统，这个问题在最近 1 或 2 次升级后出现。
还有一个解决方法。将音量调低，然后快速调高。这样做几次后，我的耳机的两个声道都恢复了。如何永久解决这个问题？
uname -r
3.11.0-15-generic
播放-l
**** List of PLAYBACK Hardware Devices ****
card 0: PCH [HDA Intel PCH], device 0: ALC270 Analog [ALC270 Analog]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 3: HDMI 0 [HDMI 0]
Subdevices: 1/1
Subdevice #0: subdevice #0
cat /proc/asound/版本
Advanced Linux Sound Architecture Driver Version k3.11.0-15-generic.
head -n 1 /proc/asound/card*/codec#*
==> /proc/asound/card0/codec#0 <==
Codec: Realtek ALC270
==> /proc/asound/card0/codec#3 <==
Codec: Intel PantherPoint HDMI
pulseaudio --check [shows no output. with sudo return permission denied to read home directory]
pulseaudio——dump-conf
### Read from configuration file: /etc/pulse/daemon.conf ###
daemonize = no
fail = yes
high-priority = yes
nice-level = -11
realtime-scheduling = yes
realtime-priority = 5
allow-module-loading = yes
allow-exit = yes
use-pid-file = yes
system-instance = no
local-server-type = user
cpu-limit = no
enable-shm = yes
flat-volumes = no
lock-memory = no
exit-idle-time = 20
scache-idle-time = 20
dl-search-path = /usr/lib/pulse-4.0/modules
default-script-file = /etc/pulse/default.pa
load-default-script-file = yes
log-target = auto
log-level = notice
resample-method = speex-float-1
enable-remixing = yes
enable-lfe-remixing = no
default-sample-format = s16le
default-sample-rate = 44100
alternate-sample-rate = 48000
default-sample-channels = 2
default-channel-map = front-left,front-right
default-fragments = 8
default-fragment-size-msec = 10
enable-deferred-volume = yes
deferred-volume-safety-margin-usec = 1
deferred-volume-extra-delay-usec = 0
shm-size-bytes = 0
log-meta = no
log-time = no
log-backtrace = 0
rlimit-fsize = -1
rlimit-data = -1
rlimit-stack = -1
rlimit-core = -1
rlimit-rss = -1
rlimit-as = -1
rlimit-nproc = -1
rlimit-nofile = 256
rlimit-memlock = -1
rlimit-locks = -1
rlimit-sigpending = -1
rlimit-msgqueue = -1
rlimit-nice = 31
rlimit-rtprio = 9
rlimit-rttime = 1000000
amixer-c 0 复制代码
Simple mixer control 'Master',0
Capabilities: pvolume pvolume-joined pswitch pswitch-joined
Playback channels: Mono
Limits: Playback 0 - 87
Mono: Playback 67 [77%] [-15.00dB] [on]
Simple mixer control 'Headphone',0
Capabilities: pvolume pswitch
Playback channels: Front Left - Front Right
Limits: Playback 0 - 87
Mono:
Front Left: Playback 87 [100%] [0.00dB] [on]
Front Right: Playback 87 [100%] [0.00dB] [on]
Simple mixer control 'Speaker',0
Capabilities: pvolume pswitch
Playback channels: Front Left - Front Right
Limits: Playback 0 - 87
Mono:
Front Left: Playback 0 [0%] [-65.25dB] [off]
Front Right: Playback 0 [0%] [-65.25dB] [off]
Simple mixer control 'PCM',0
Capabilities: pvolume
Playback channels: Front Left - Front Right
Limits: Playback 0 - 255
Mono:
Front Left: Playback 255 [100%] [0.00dB]
Front Right: Playback 255 [100%] [0.00dB]
Simple mixer control 'Mic',0
Capabilities: pvolume pswitch
Playback channels: Front Left - Front Right
Limits: Playback 0 - 31
Mono:
Front Left: Playback 0 [0%] [-34.50dB] [off]
Front Right: Playback 0 [0%] [-34.50dB] [off]
Simple mixer control 'Mic Boost',0
Capabilities: volume
Playback channels: Front Left - Front Right
Capture channels: Front Left - Front Right
Limits: 0 - 3
Front Left: 3 [100%] [36.00dB]
Front Right: 3 [100%] [36.00dB]
Simple mixer control 'IEC958',0
Capabilities: pswitch pswitch-joined
Playback channels: Mono
Mono: Playback [off]
Simple mixer control 'Capture',0
Capabilities: cvolume cswitch
Capture channels: Front Left - Front Right
Limits: Capture 0 - 31
Front Left: Capture 18 [58%] [10.50dB] [on]
Front Right: Capture 18 [58%] [10.50dB] [on]
Simple mixer control 'Auto-Mute Mode',0
Capabilities: enum
Items: 'Disabled' 'Enabled'
Item0: 'Enabled'
Simple mixer control 'Digital',0
Capabilities: cvolume
Capture channels: Front Left - Front Right
Limits: Capture 0 - 120
Front Left: Capture 60 [50%] [0.00dB]
Front Right: Capture 60 [50%] [0.00dB]
pacmd 转储卷
No PulseAudio daemon running, or not running as session daemon.
sudo pactl 信息
Server String: unix:/run/user/1000/pulse/native
Library Protocol Version: 28
Server Protocol Version: 28
Is Local: yes
Client Index: 28
Tile Size: 65472
User Name: shantanu
Host Name: shantanu-voillo
Server Name: pulseaudio
Server Version: 4.0
Default Sample Specification: s16le 2ch 44100Hz
Default Channel Map: front-left,front-right
Default Sink: alsa_output.pci-0000_00_1b.0.analog-stereo
Default Source: alsa_input.pci-0000_00_1b.0.analog-stereo
Cookie: 381c:e256
答案1
尝试以下设置alsamixer- 打开终端并输入alsamixer：
您可以使用q和w来调整左右声道。
答案2
如果您已检查过连接，且连接良好，并且确定是更新导致了问题，则以下链接可能会有所帮助：
你可以更新系统或尝试清除然后安装
alsa-utils。你可以切换到使用以前的内核版本启动。
答案3
从顶部开始。运行扬声器测试应用程序来弄清楚发生了什么。
如果您可以听到两个笔记本电脑扬声器的声音，请继续插入耳机插头的插孔。
如果两个扬声器都能听到声音，但只从一个耳机中听到，那么问题就出在连接器上（因为您说过已经在另一台设备中检查过耳机）。
如果确实如此，也许对插入的千斤顶施加一些压力可能会有所帮助。
答案4
起初，我的音频设备都无法正常工作。然后我按照以下说明操作，让扬声器正常工作：https://help.ubuntu.com/community/SoundTroubleshooting
但耳机里还是没有声音。然后我按照以下说明操作：
那时只有我的右耳能听见。
最终解决问题的方法是打开alsamixer并更改loopback为disabled。突然间，我的两只耳朵都能听到声音了。