我有 linux2.6.38，但我不知道我的声音驱动程序名称是什么，无法改变声音级别。当我写道：
[root@FriendlyARM /]# amixer -D pulse sset Master 50% ALSA lib control.c:902:(snd_ctl_open_noupdate) Invalid CTL pulse amixer: Mixer attachment pulse 错误: 没有那个文件或目录
我有一台搭载 Linux 操作系统的友好 Arm 嵌入式设备，这是 Amixer 的详细信息：
[root@FriendlyARM /]# amixer
Simple mixer control 'Headphone',0
Capabilities: pvolume penum
Playback channels: Front Left - Front Right
Limits: Playback 0 - 127
Mono:
Front Left: Playback 121 [95%] [0.00dB]
Front Right: Playback 121 [95%] [0.00dB]
Simple mixer control 'Headphone Playback ZC',0
Capabilities: pswitch penum
Playback channels: Front Left - Front Right
Mono:
Front Left: Playback [off]
Front Right: Playback [off]
Simple mixer control 'Speaker',0
Capabilities: pvolume penum
Playback channels: Front Left - Front Right
Limits: Playback 0 - 127
Mono:
Front Left: Playback 121 [95%] [0.00dB]
Front Right: Playback 121 [95%] [0.00dB]
Simple mixer control 'Speaker AC',0
Capabilities: volume volume-joined penum
Playback channels: Mono
Capture channels: Mono
Limits: 0 - 5
Mono: 0 [0%]
Simple mixer control 'Speaker DC',0
Capabilities: volume volume-joined penum
Playback channels: Mono
Capture channels: Mono
Limits: 0 - 5
Mono: 0 [0%]
Simple mixer control 'Speaker Playback ZC',0
Capabilities: pswitch penum
Playback channels: Front Left - Front Right
Mono:
Front Left: Playback [off]
Front Right: Playback [off]
Simple mixer control 'PCM Playback -6dB',0
Capabilities: pswitch pswitch-joined penum
Playback channels: Mono
Mono: Playback [off]
Simple mixer control 'Mono Output Mixer Left',0
Capabilities: pswitch pswitch-joined penum
Playback channels: Mono
Mono: Playback [off]
Simple mixer control 'Mono Output Mixer Right',0
Capabilities: pswitch pswitch-joined penum
Playback channels: Mono
Mono: Playback [off]
Simple mixer control 'Playback',0
Capabilities: volume penum
Playback channels: Front Left - Front Right
Capture channels: Front Left - Front Right
Limits: 0 - 255
Front Left: 255 [100%] [0.00dB]
Front Right: 255 [100%] [0.00dB]
Simple mixer control 'Playback De-emphasis',0
Capabilities: enum
Items: 'None' '32Khz' '44.1Khz' '48Khz'
Item0: 'None'
Simple mixer control 'Capture',0
Capabilities: cvolume penum
Capture channels: Front Left - Front Right
Limits: Capture 0 - 255
Front Left: Capture 209 [82%] [7.00dB]
Front Right: Capture 209 [82%] [7.00dB]
Simple mixer control '3D',0
Capabilities: volume volume-joined pswitch pswitch-joined penum
Playback channels: Mono
Capture channels: Mono
Limits: 0 - 15
Mono: 0 [0%] Playback [off]
Simple mixer control '3D Filter Lower Cut-Off',0
Capabilities: enum
Items: 'Low' 'High'
Item0: 'Low'
Simple mixer control '3D Filter Upper Cut-Off',0
Capabilities: enum
Items: 'High' 'Low'
Item0: 'High'
Simple mixer control 'ADC High Pass Filter',0
Capabilities: pswitch pswitch-joined penum
Playback channels: Mono
Mono: Playback [off]
Simple mixer control 'ADC Polarity',0
Capabilities: enum
Items: 'No Inversion' 'Left Inverted' 'Right Inverted' 'Stereo Inversion'
Item0: 'No Inversion'
Simple mixer control 'ALC Attack',0
Capabilities: volume volume-joined penum
Playback channels: Mono
Capture channels: Mono
Limits: 0 - 15
Mono: 2 [13%]
Simple mixer control 'ALC Decay',0
Capabilities: volume volume-joined penum
Playback channels: Mono
Capture channels: Mono
Limits: 0 - 15
Mono: 3 [20%]
Simple mixer control 'ALC Function',0
Capabilities: enum
Items: 'Off' 'Right' 'Left' 'Stereo'
Item0: 'Off'
Simple mixer control 'ALC Hold Time',0
Capabilities: volume volume-joined penum
Playback channels: Mono
Capture channels: Mono
Limits: 0 - 15
Mono: 0 [0%]
Simple mixer control 'ALC Max Gain',0
Capabilities: volume volume-joined penum
Playback channels: Mono
Capture channels: Mono
Limits: 0 - 7
Mono: 7 [100%]
Simple mixer control 'ALC Min Gain',0
Capabilities: volume volume-joined penum
Playback channels: Mono
Capture channels: Mono
Limits: 0 - 7
Mono: 0 [0%]
Simple mixer control 'ALC Mode',0
Capabilities: enum
Items: 'ALC' 'Limiter'
Item0: 'ALC'
Simple mixer control 'ALC Target',0
Capabilities: volume volume-joined penum
Playback channels: Mono
Capture channels: Mono
Limits: 0 - 15
Mono: 4 [27%]
Simple mixer control 'DAC Deemphasis',0
Capabilities: pswitch pswitch-joined penum
Playback channels: Mono
Mono: Playback [off]
Simple mixer control 'DAC Polarity',0
Capabilities: enum
Items: 'No Inversion' 'Left Inverted' 'Right Inverted' 'Stereo Inversion'
Item0: 'No Inversion'
Simple mixer control 'Input',0
Capabilities: volume pswitch penum
Playback channels: Front Left - Front Right
Capture channels: Front Left - Front Right
Limits: 0 - 63
Front Left: 23 [37%] [0.00dB] Playback [on]
Front Right: 23 [37%] [0.00dB] Playback [on]
Simple mixer control 'Left Boost Mixer Boost',0
Capabilities: pswitch pswitch-joined penum
Playback channels: Mono
Mono: Playback [on]
Simple mixer control 'Left Input Mixer LINPUT1',0
Capabilities: pswitch pswitch-joined penum
Playback channels: Mono
Mono: Playback [on]
Simple mixer control 'Left Input Mixer LINPUT2',0
Capabilities: pswitch pswitch-joined penum
Playback channels: Mono
Mono: Playback [off]
Simple mixer control 'Left Input Mixer LINPUT3',0
Capabilities: pswitch pswitch-joined penum
Playback channels: Mono
Mono: Playback [off]
Simple mixer control 'Left Output Mixer Boost Bypass',0
Capabilities: volume volume-joined pswitch pswitch-joined penum
Playback channels: Mono
Capture channels: Mono
Limits: 0 - 7
Mono: 2 [29%] [-15.00dB] Playback [off]
Simple mixer control 'Left Output Mixer LINPUT3',0
Capabilities: volume volume-joined pswitch pswitch-joined penum
Playback channels: Mono
Capture channels: Mono
Limits: 0 - 7
Mono: 2 [29%] [-15.00dB] Playback [off]
Simple mixer control 'Left Output Mixer PCM',0
Capabilities: pswitch pswitch-joined penum
Playback channels: Mono
Mono: Playback [on]
Simple mixer control 'MIC Boost Gain',0
Capabilities: volume penum
Playback channels: Front Left - Front Right
Capture channels: Front Left - Front Right
Limits: 0 - 3
Front Left: 3 [100%]
Front Right: 3 [100%]
Simple mixer control 'Noise Gate',0
Capabilities: pswitch pswitch-joined penum
Playback channels: Mono
Mono: Playback [off]
Simple mixer control 'Noise Gate Threshold',0
Capabilities: volume volume-joined penum
Playback channels: Mono
Capture channels: Mono
Limits: 0 - 31
Mono: 0 [0%]
Simple mixer control 'Right Boost Mixer Boost',0
Capabilities: pswitch pswitch-joined penum
Playback channels: Mono
Mono: Playback [off]
Simple mixer control 'Right Input Mixer RINPUT1',0
Capabilities: pswitch pswitch-joined penum
Playback channels: Mono
Mono: Playback [on]
Simple mixer control 'Right Input Mixer RINPUT2',0
Capabilities: pswitch pswitch-joined penum
Playback channels: Mono
Mono: Playback [off]
Simple mixer control 'Right Input Mixer RINPUT3',0
Capabilities: pswitch pswitch-joined penum
Playback channels: Mono
Mono: Playback [off]
Simple mixer control 'Right Output Mixer Boost Bypass',0
Capabilities: volume volume-joined pswitch pswitch-joined penum
Playback channels: Mono
Capture channels: Mono
Limits: 0 - 7
Mono: 2 [29%] [-15.00dB] Playback [off]
Simple mixer control 'Right Output Mixer PCM',0
Capabilities: pswitch pswitch-joined penum
Playback channels: Mono
Mono: Playback [on]
Simple mixer control 'Right Output Mixer RINPUT3',0
Capabilities: volume volume-joined pswitch pswitch-joined penum
Playback channels: Mono
Capture channels: Mono
Limits: 0 - 7
Mono: 2 [29%] [-15.00dB] Playback [off]