Volume boost

Hi all,

I have been burning CDRs with Audition CS5. The discs in question are compilations I have made up from various CDs old and new with a lot of varation on listening volumes. As you can imagine the older CDs are quieter than the newer ones. I decided to convert all the files to -3db. The problem I have come up against is in some instances a certain song may only reach -3db in only ONE instance in that song and the remainder of the song is below -3db which makes it sound quieter than other songs on that compilation. Is there anything within CS5 to slightly boost the quieter parts of that song or is there a separate program that can do this. Any thoughts would be most welcome.