Currently the easiest way to remove the background noise from a video is to use Noisles.
Just follow these simple steps:
On the main page choose the video you wish to de-noise and click Proceed
Click Remove noise button and wait couple seconds for the processing to finish
Check the result using video preview
Click Prepare and download video button and wait couple more seconds once again for processing
That's it! You're done, and now your video sounds perfect. You may share it with your audience and be confident it will be a pleasure to listen.
Optionally you may try different algorithms for noise reduction by selecting them in the drop-down left to the Remove noise button. They produce different results for different noise environments, so it's worth playing with them.