Best method to increase a low volume recording..(audio from a CCTV).

Hello,

I have an audio/ video recording from my security camera. The audio volume is quiet and has background noise. I have normalized the audio and manually plucked away unwanted sounds. I also tried most of the sofware features however my results have not been very good. I typically end up with thin, tinny sound and the speech is hard to understand. I need the audio to be good enough to use in Court. I am new to the Audition Software and I really need someone to nudge me in the right direction.  

I attached a portion of the audio file. Feel free to give it a shot.

Thanks in advance for your input!