[Rogerio De souza]

Hello, you will not be able to import the audio of that video avi properly for Sony Vegas because it is MP2 audio (MPEG Layer 2) and Sony Vegas does not support this type of audio in .avi files .
You’ll even be able to import the video from the Xvid codec installed on your Windows but not audio .
If you want to install the Xvid codec to test, install it according to your Sony Vegas, or if your Vegas is 32 bits install the 32-bit codec (if its still being Windows 64-bit), and if your Vegas is 64-bit install the 64-bit codec … the link below you can download, there is an installer of over 10MB and also the individual installers for 32 or 64 bits, and are what I recommend for you .
https://www.divx-digest.com/software/xvid.html
The next time you record something using Bandicam to then edit in Vegas, set the audio to PCM type Bandicam … this will cause the audio stays much higher than would be if MP2, but this will be accepted by Vegas .
Well, you should be reading many mistakes in this text, do not speak your language .