Constant unwanted noise while recording with lavalier mic in laptop

Hello, (windows 10, Audacity version 2.3.1)
I record voiceovers and I am having this problem for few days. This problem was not there earlier with my laptop. The battery of my laptop does not work properly so it always runs on electricity. And I have never had any issue before this. There is no noisy environment where I record my voice. I have tried 3 microphones (3.5 mm jack, lavalier condenser microphone - Never Had any issues like this before ) for this and the same noise is being seen in all three.
I think this sound is from the fan of the laptop or there is some other reason about which I am not aware. I have searched it in many places but to no avail so if anyone can tell what is the reason behind this or any solution to fix it, So this will be helpful.

I’m also attaching a recording with this post and an image

Are you in a 50Hz power area such as England or continental Europe? Your sample has a very serious 50Hz hum tone. That’s a little too low in pitch to be easily audible, but it sticks out immediately on the Audacity analysis tools.

The battery of my laptop does not work properly so it always runs on electricity.

50Hz electricity? It’s not unusual for manufacturers to use the electrical inertia of the battery to help filter the wall power and make it well-behaved enough to run the computer. It’s cheap filtering.

Except you have no battery.

I think I’d fix that first.


thank you Coz

Well, I have never had a problem with this before, now I feel the same way that there has been a problem due to this. Maybe for a few days, my laptop’s wifi also does not show sometimes due to this reason. And the buttons on my keyboard also work when I press hard, and this problem is only where the laptop charger is connected. Could this also be a reason? Because even when the battery of my laptop was not working, the recording was going well.

Basically, I am from India. and the attached sample was amplified (33dB), you can see the difference in the attached image.
In the original recording, this noise is not that much but it can be heard, and removing it becomes a huge task.
I will add another sample to this in the next reply, without any amplification.