Hello,
I just discover Audacity and before learning this program into details, i have following question:
Can I mix a voice record (made with Audacity) with an MP3 music record (already existing) and change volume of both, in the sense that when hearing the voice the music is dimmed (manually during mixing or automtically by Audacity). The result must be a stereo MP3 file I will use in slide projections.
Tkx to save me time to start with this program 
Yes you can - Audacity is designed to be a mult-track audio editor.
You will need to import the music track - and then record your voice track as a new track - actually you may find it easier to record the voice track first and then create a new stereo track and import the music track into a new stereo track.
You can then select each track in turn and use the envolope tool (icon has two triangles pointing towards each other with a dot in the middle and a blue line through it). By dragging the blue line around and creating various datum points you can control the amplitude of each track.
When you set Audacity to play (providing you habe not âMutedâ either of the tracks) it will play both tracks together, showing you what the final mix will sound like. When you Export the project to WAV, MP3 or whatever - then Audacity will mix the tracks down into a single stereo pair for your production music file.
Have fun,
WC
Tkx Waxcylinder, I start learning the program and will apply your solution.
I have read this dialogue, but I still have a few questions.
I have one track with a music bed and the second with voice. I have tried to record the third track as a âmixdownâ of tracks 1 & 2, but had no luck. (Is this possible? - neither tracks were muted) When I tried it, I removed my headset/mic from the computer. I recorded the roomâs ambient sound and the âtinnyâ music and voice coming from the computer speaker, in other words, I must have recorded the computerâs external speaker. I tired the same thing again, only this time I left my headset/Mic jack in the computer. I had no luck here either. So that is issue #1.
Issue #2, is I tried your suggestion of exporting the project onto a removeable disc (so I can use it on another computer for another program), but upon playback, I lost track #1 (music bed) and only had the voice track.
Iâm sure this is operator error on my part, but I canât seem to see what I am doing wrong.
Would you please help?
If Audacity is picking up ambient PC noises, you probably have the recording device set to your PCâs internal mixer, which is picking up every sound on your PC, internal mic, sounds from applications, browsers, Outlook chimes for incoming messages, etc.
Go to Edit>Preferences>Recording Device and change it to whatever your mic is named, Blue Snowball, etc.