Video for work, but I can´t get the background clear

[Sabine]

Dear all,

I made a small introduction video that I need to apply for work, and my laptop creates this incredible, high pitched background noise. I tried the obvious in Audacity, I killed the sound, but to the cost of a totally muffled sound.
Would anyone know, if it is still possible to save this video? I find it really good and would not like to make it from the mobile phone one again.
Any ideas appreciated.

Here is the link to the video:
https://www.youtube.com/watch?v=HV1FgaXe9Ds&t=2s

[jagabo]

In Audacity:

Mark a second or two of just the noise at the start (or elsewhere) of the clip. Use Effect -> Noise Reduction -> Get Noise Profile. Then mark the entire clip and select Effect -> Noise Reduction, set Noise reduction to about 20 dB. Press OK. That should work pretty well. The higher the NR setting the more distortion you'll get.

Alternate method:

Mark a second or two of just the noise at the start (or elsewhere) of the clip. Use Analyze -> Plot Spectrum to see a graph of frequencies. Enlarge the Window to full screen for best accuracy. Take note of the frequency of the highest peaks. I got 738, 884, 3494, 4000, and 4505 (the latter three are responsible for most of the whine). Mark the entire clip then select Effect -> Notch filter. Set Frequency to one of those peaks. Set Q to 12 (very narrow frequency range). Press OK. Repeat for each of the peaks. A sample with just the three highest frequencies remove is attached.

[Sabine]

That is so amazing! I did all that yesterday, but only for the highest pitch, it somehow did not cross my mind - although it is so logical - to simply repeat the process for the other frequencies. Thank you so much for your input, I was about to give up.

Thanks a million for your great help!

[jagabo]

You're welcome.

By the way, in the future use a lapel mic or a boom mic. The idea is to get the mic as close as possible to the person speaking. You'll get a much clearer voice, and less noise and echo. Of course, this may not be possible with a smartphone.