Audio Investigation: Background Voice Clarification

I have a ~2 hour audio file that requires careful listening and enhancement to clarify background voices for investigative purposes. The quality of the audio is poor with significant noise, so your expertise in audio enhancement will be crucial.

Ideal skills and experience:
- Proficiency in audio editing software
- Experience in noise reduction techniques
- Ability to discern and isolate background voices
- Strong attention to detail
- Experience in investigative audio analysis