How do I check that?

Menu bar...Options > Preferences > (TAB) Audio Device 

Yes, mine is set to Microsoft Sound Mapper as well, anything else you can do to help?

Is it just one particular media format that causes this problem, or can't you hear audio from any format (e.g. mp3, WAV, other video formats etc.)?

My problem is from all video formats.

If you can hear audio formats OK, but not video formats, then it sounds like 3rd party codecs may be involved and not decoding the audio to Vegas' liking. Do you have a codec pack or ffdshow installed?

Or maybe you simply have the audio volume turned down or muted on your audio track or mixing console or master bus.

audio*

no i do not have ffdshow installed, and if it was muted on the mixing console then i wouldn't be able to hear it when it has been rendered,

maybe its third party codecs interfering.

What are you program are you playing the rendered file in (when you can hear it), and is it through the same speakers that Vegas uses?

wait, third party codecs are not interfering

literally no audio works on vegas pro

I use Fraps, thats where the audio comes from, when I check raw files the sound is there, but when trying to edit in Vegas Pro I only hear it when it's renderred.

Guess I'm going to have to delete the software because I have no use for it when sound doesn't work.

Money well wasted :(

What other video formats did you try?  

studio premium: Audio fails to render in Ver 13, plays on time line but no sound on rendered files in ver 13

Can you delete both of your current comments and start a new topic in the Vegas Movie Studio (Platinum version of which you probably have) section of the forum telling us which template you are using to render.