I need some help with a audio clip, i used a ipad to record about 15-20 minutes of some conversations, there is alot of background noice from a air conditioning system and alot of other audio/voice that I want to get rid of so I can hear the main piece clearly. I have tried amply and noise reduction with no luck, im willing to pay a professional to help clean this up… if anyone is interested, please contact me.
Sometimes filtering/equalization can help but if you can’t understand what’s being said there’s probably nothing you can do.
Noise reduction works best when you have a constant low-level background noise… It works best when you don’t really need it. (Pros still record in soundproof studios with good equipment and good mic positioning, etc.)
If there are any low frequencies (below around 100hz) that’s just noise and it can be filtered out. Boosting the higher frequencies (above maybe 4kHz)can bring-out the “T” & “S” sounds which can help with intelligibility, but of course it will also boost high frequency noise. The highest frequencies (maybe above 8kHz) can usually be filtered-out too.
Usually the human brain is the best “filter” and if you can make-out what’s being said, a written transcript is often the best solution. Or subtitles if you’re making a video, or re-record the audio if you’re making a movie, etc.
You can Google forensic audio enhancement, but there’s only so-much anybody can do
All that and Audacity can’t be used for surveillance, law enforcement and conflict resolution. There’s no way to certify the tools or the correction pathway.
You were only in bad shape with “normal” background noises, but throw other voices in and that’s the end of the world. We can’t split voices apart.