'Input Monitor' setting got FUBAR on Vista

[mojomoneyman]

I just installed Audacity 1.3.10 tonight. at first i couldnt get it to record but i eventually figured it out after adjusting some settings.

i was putting down some bass. then i was going to switch over to an acoustic guitar with a pick up. I unplugged the bass jack from the line-in on the front of my Gateway laptop. then as i was plugging in the jack for my acoustic I got what i can only call the audio version of the blue screen of death (if youve never heard of that you might have to google it)

but basically, i put the jack in then pulled it back out and next thing i know its sounds like a fire alarm going off on my pc, like loud as hell amp feedback coming from my crummy little built in laptop speakers.

i couldnt figure out how to shut it off, it was so loud, in a panic i pulled the battery out to kill the power. then i rebooted, and there was a windows repair that ran. then it restarted, and as soon as it got booted up that awful noise came on again.

this time i monkeyed around with the audio settings. eventually i figured out if i muted the 'input monitor' setting it would kill the sound, while leaving the main audio in tact.

so now i guess the main audio is okay after all, (at first i was worried i fried my sound card or something) but apparently the 'input monitor' is out of commission. to be honest i'm not sure what this setting is really for.

anyone know how i might go about fixing this, or is something on my system FUBARd? any advice appreciated.

[steve]

My guess is that your laptop has an internal microphone and when you unplugged, Windows "helpfully" switched it on. Trouble being that you probably had both your recording volume set quite high, and were monitoring the input through speakers, so as soon as the microphone became active you got feedback (sound from the speakers picked up by the microphone, amplified, then back out from the speakers and round and round it goes.) Turn all the volume levels down (recording and playback levels), then spend some time with the sound card control panel/mixer in Windows so that you can work out how it all works.

[mojomoneyman]

thanks for the advice. i tried what you said. the feedback goes away if i turn my microphone levels all the way down. then i can switch on the input monitor and it is fine. before that the threshold was at 45 on the mixer level. i also noticed when i muted the 'pc speaker' level this amplified the feedback.

so, now it looks like i have to live without a mic input?

[steve]

so, now it looks like i have to live without a mic input?

No, you should still be able to use the microphone, but you can't have the microphone playing loudly through speakers at the same time. If you either, use headphones, or mute the microphone playback, it should work correctly.