How can I clean and isolate audio?

[Ah_Dziz]

Reverb jacks up phase data which is a major part of most of the pitch detection methods there are.

[BertKoor]

Room acoustics or phase is not the issue here, as shown by the works of Donkey Tugger.
To me that sounds like a fair rendition in midi of the recorded audio.

[billinder33]

I was about to give up on converting audio to MIDI when I had this idea: what if I clean the audio file to remove all noise and leave just the acoustic guitar sound? That should be possible. It doesn't have to sound "nice." The existing audio track doesn't sound very "nice" anyway. I just need to make sure that nothing is left but some part of each note sound bite that some software can use to identify the note. But I'm not really sure where to begin. Should I use an EQ? Would IQ4gui help me with that? An EQ works on frequencies. I think that is not what I need. Or is it?

Assume this is a note:

---x-x---o-oxo-OOOO-o-xo--ox----x-x-

Dashes and x'es are garbage I want to get rid of. Small o's are legitimate note sounds, but of poor quality. Capital O's are legitimate note sounds of good quality. Is there anything I can do separate the wheat from the chaff? I know quite a few tricks to sharpen/enhance images, but not sounds.

I don't own this plugin, but it was free for a while and did a really good job cleaning audio on audio files like this:

https://product.supertone.ai/clear

They offer a demo that injects noise every 60 seconds, but if you only need it for this one task you could probably bounce the output a couple of times and splice them together to remove the noise.

[EfreetiSultan]

I've attempted this and it just doesn't work yet.
But spectralayers is the best you can do for now

Izotope rx is complete bogus.. Rarely works at all. It's good for very simple stuff though. Like batch processing

[mjolnir]

Audacity / Tenacity / Audacium has a noise reduction function also.
I just saw a YouTube video demoing it yesterday.

[bluesawsq]

You can get pretty good MIDI conversion using Melodyne 5.

XIFj_melodyne5.zip

This is without any preprocessing, with default settings. Only manual adjustment was a slight increase of "Potential Notes Slider".

Here is an audio example of the MIDI played using NI Session Guitarist - Picked Acoustic:
https://voca.ro/1n6TBvUQunpn

[lmv]

I don't own this plugin, but it was free for a while and did a really good job cleaning audio on audio files like this:
https://product.supertone.ai/clear

I tried their demo and it didn't work. I'm on Linux. Most Windows plugins will work, but some won't.

I've attempted this and it just doesn't work yet.
But spectralayers is the best you can do for now
Izotope rx is complete bogus.. Rarely works at all. It's good for very simple stuff though. Like batch processing

Audacity / Tenacity / Audacium has a noise reduction function also.
I just saw a YouTube video demoing it yesterday.

Thank you all. I am not very interested in cleaning anymore. I've lost my faith in the MIDI converters. Even with cleaning, I don't think they can get it right or will be able to any time soon.

You can get pretty good MIDI conversion using Melodyne 5.
XIFj_melodyne5.zip
This is without any preprocessing, with default settings. Only manual adjustment was a slight increase of "Potential Notes Slider".

Here is an audio example of the MIDI played using NI Session Guitarist - Picked Acoustic:
https://voca.ro/1n6TBvUQunpn

Hey, that one really sounds promising! I am impressed. Thank you for trying and sharing the files. But I need free tools to achieve my goals. The perks of being poor.

[mjolnir]

sorry it didn't work out, i can relate for much of the same reasons.