How to delete noise?

I know, the name of topic sounds stupid. I tried everything. Internet, trying… and nothing works.

I recorded something on my electric piano to my computer by microphone jack. It is good, but piano has quite loud noise. I removed the noise in Audacity, but there is still some. I want only piano voice, not noise.

If you have some suggestions, thank you.


Don’t worry about it and don’t double post. We see you. I need to step away for a while.


I know, I’m sorry. I just forgot to add links to my recordings. First topic didn’t have it.

Are these test files before after you attempted to use the “noise removal”?

If they are before, my first suspect would be the windows “sound enhancements” if you are on a windows machine. If they are after, please post a “before” sample so we can hear what it really sounds like.

FYI most computer “Microphone jacks” are not designed to accept a line-level stereo signal. However your sample recordings are clearly stereo and don’t have any overload distortion so I’m guessing your input is really a “combo” input that will take either microphone or line signals.

Obvious test (which maybe you already did), plug a set of headphones directly into the output on your keyboard and see if you hear the same noise.

Otherwise look through the control panels for your sound card and see if there are any “enhancements” enabled.

I deleted every effect on my sound card. Here are my recordings: - BEFORE - AFTER

That noise is most likely electrical noise from your computer finding it’s way into the input amplifiers on your soundcard. There’s a smaller chance that it is coming from the digital electronics inside your piano (I’m assuming you are playing some sort of electronic keyboard). Either way there is no good way to remove it once it is in the recording.

Question: Do you have the piano connected computer via a cable? (which is what I thought your first post was saying), or do you have an actual microphone pointed at the instrument? The reason I ask is there are some soft thumps at the end of the recording that make me think the latter.

Assuming the problem is the sound card, most likely the only real cure is an external sound interface of some sort.

Tell us more about your setup, what brand/model keyboard? what brand/model computer?

Yes, I record via a cable. It is 3.5mm jack cable. One is in piano and one in micrphone input in my computer.

Computer: Lenovo y500
Piano: Korg LP180

Piano has 2 inputs for 3.5mm jacks. I used one for recording and one for headphones. It also has a MIDI OUT input. Should I buy MIDI cable and record with it? It is quite expensive and every cable, I found has 2 MIDI outputs. I think it is because of piano should have MIDI IN and MIDI OUT no?

I’m only amateur in audio recording. I’m sorry, if I’m wrong.

Your best bet is probably going to be an external sound interface. The Behringer UCA-202 (~$30) is very popular among several of us on this forum, and should work well for this purpose. You will also need a 3.5mm to Phono connector cable to hook it up (looks like this:

The Behringer does not have any input level control, so you will need to use the volume control on the Korg to set the level for recording. This might end up being too loud or soft in the headphones you use for monitoring if they are plugged into the second headphone jack on the Korg, but you can use the headphone jack on the Behringer instead and use the headphone volume there to get your monitoring level comfortable.

What you got using the microphone input on your laptop is actually a lot better than I would have expected, most will not accept line-level signals at all nor record in stereo.

“recording midi” is different. A Midi recording is more akin to the paper roll in a old player piano, it’s the sequence of notes and not the actual sound. Audacity does not support MIDI but there are plenty of tools out there that do.

According to it’s manual the Korg has a 3-prong (grounding) power cord, and I’ll bet your laptop’s power supply has one as well. Multiple ground paths can sometimes make this sort of noise worse than it might otherwise be. You might try another recording with the laptop disconnected from the power supply (running on battery) to see if that is any different.

Thank you so much,
I’ll try it.

I find out, that it is not the piano’s fault. It is because of cable. I turned the volume on the piano up (maximum) and turned microphone jack volume down to half. A lot better! No noise!