I am making an iPhone app to record and play the human voice back just like Talking Tom. Everything works fine, but I am not able to figure out how do I remove the background noise in recorded audio file?
I know the low pass filtering is an option to do so, but I dont know how to code this? Can anyone help me to implement a low pass filter or something else to remove the background noise from a recorded audio file in iOS.
I don't do ios, but there is an example of a low pass filter for accelerometer for the iphone at Accelerometer Low Pass Filtering which you may be able to adapt for your use.
Basically the filtered value at time x = unfiltered value at time x * alpha + filtered value at time x-1 * (1- alpha)
And for the filtered value at time 0 = unfiltered value at time 0 * alpha (assumes that the unfiltered value at time -1 is 0)
You will need to set the alpha using trial and error. Perhaps somewhere in the range 0.01 to 0.1 might be useful.
