Adaptive filter to remove constantly repeating noises

Hi, I am trying to create an audio filter that will remove any repetitive noise. Like a fan in the room. I also want it to be able to remove any new noise that keeps repeating for a certain amount of time, say 10seconds. I will greatly appreciate any help. Thanks

Answer 1

[Walter Roberson]

My understanding is that fans are generally not repeating noise: that instead, they are white noise, and thus random.

http://www.fan2012.org/gb/fan-noise.html indicates,

The two main mechanisms are tonal noise at harmonics of the blade passing frequency and broadband noise due to leading-edge, trailing-edge and tip clearance noisen respectively

The broadband noise is going to be a problem for filtering: pretty much by definition, broadband noise will exceed your filter bandwidth.