Hallo Marvin,
du treuer Helfer 
internes oder externes Mikrofon? Was für ein Notebook hast Du
eigentlich?
Es handelt sich um ein Headset. Das Notebook ist ein LG TX-ADGDG, Baujahr Anfang 2006, glaube ich.
Starte mal den alsamixer und sieh nach, ob Du das Mikro nicht
zufällig stumm geschaltet hast.
Nein, es ist voll aufgedreht.
Noch besser wäre es, mit
amixer -i
Hier ist der Output:
Simple mixer control ‚Master‘,0
Capabilities: pvolume pvolume-joined pswitch pswitch-joined
Playback channels: Mono
Limits: Playback 0 - 64
Mono: Playback 45 [70%] [-19.00dB] [off]
Simple mixer control ‚Headphone‘,0
Capabilities: pswitch
Playback channels: Front Left - Front Right
Mono:
Front Left: Playback [on]
Front Right: Playback [on]
Simple mixer control ‚PCM‘,0
Capabilities: pvolume
Playback channels: Front Left - Front Right
Limits: Playback 0 - 255
Mono:
Front Left: Playback 225 [88%] [-6.00dB]
Front Right: Playback 225 [88%] [-6.00dB]
Simple mixer control ‚Front‘,0
Capabilities: pvolume pswitch
Playback channels: Front Left - Front Right
Limits: Playback 0 - 64
Mono:
Front Left: Playback 60 [94%] [-4.00dB] [on]
Front Right: Playback 60 [94%] [-4.00dB] [on]
Simple mixer control ‚Mic‘,0
Capabilities: pvolume pswitch
Playback channels: Front Left - Front Right
Limits: Playback 0 - 65
Mono:
Front Left: Playback 60 [92%] [25.00dB] [on]
Front Right: Playback 60 [92%] [25.00dB] [on]
Simple mixer control ‚IEC958‘,0
Capabilities: pswitch pswitch-joined
Playback channels: Mono
Mono: Playback [off]
Simple mixer control ‚IEC958 Default PCM‘,0
Capabilities: pswitch pswitch-joined
Playback channels: Mono
Mono: Playback [on]
Simple mixer control ‚Capture‘,0
Capabilities: cvolume cswitch
Capture channels: Front Left - Front Right
Limits: Capture 0 - 35
Front Left: Capture 35 [100%] [35.00dB] [on]
Front Right: Capture 35 [100%] [35.00dB] [on]
Simple mixer control ‚Capture‘,1
Capabilities: cvolume cswitch
Capture channels: Front Left - Front Right
Limits: Capture 0 - 35
Front Left: Capture 0 [0%] [0.00dB] [on]
Front Right: Capture 0 [0%] [0.00dB] [on]
Simple mixer control ‚Capture‘,2
Capabilities: cvolume cswitch
Capture channels: Front Left - Front Right
Limits: Capture 0 - 35
Front Left: Capture 0 [0%] [0.00dB] [on]
Front Right: Capture 0 [0%] [0.00dB] [on]
Simple mixer control ‚Caller ID‘,0
Capabilities: pswitch pswitch-joined
Playback channels: Mono
Mono: Playback [off]
Simple mixer control ‚Digital‘,0
Capabilities: cvolume
Capture channels: Front Left - Front Right
Limits: Capture 0 - 120
Front Left: Capture 111 [92%] [25.50dB]
Front Right: Capture 111 [92%] [25.50dB]
Simple mixer control ‚Input Source‘,0
Capabilities: cenum
Items: ‚Mic‘
Item0: ‚Mic‘
Simple mixer control ‚Input Source‘,1
Capabilities: cenum
Items: ‚Mic‘
Item0: ‚Mic‘
Simple mixer control ‚Input Source‘,2
Capabilities: cenum
Items: ‚Mic‘
Item0: ‚Mic‘
Simple mixer control ‚Off-hook‘,0
Capabilities: pswitch pswitch-joined
Playback channels: Mono
Mono: Playback [off]
Erkennst du etwas Auffälliges?. Zur Zeit sind meine Lautsprecher stummgeschaltet.
Tychi