Crackling noises in raw PCM files

I have some raw audio files which I load as Unsigned 8-bit PCM, Little Endian, Mono, at 29000 Hz.

The problem is that crackling noises appear whenever the sound becomes “full”. This happens in other sound editors just the same as in Audacity, so I think the files are at fault. Normalizing doesn’t help at all, while Equalization ends up ruining the rest of the sound.

First, I would like to know what exactly causes the crackling effect, from a theoretical standpoint.
Second, I would appreciate a cure for the noise. (EQ preset? A specific method to resample the raw data?)

Why 29 KHz?

The sample you posted, is 16 bit signed, according to MediaInfo.

I’m just trying to understand what you’re trying to accomplish.

Some, even most audio interfaces don’t playback 29 KHz at all, in which case your OS needs to resample to 44.1 KHz. That also happens while recording BTW, and could be the source of the cracks in the audio.

Unsigned 8-bit 29 KHz are the specifics of the raw audio files which I am importing into Audacity.
The attached Wave sample is the result of the conversion. It is an example of how the audio gets noisy with cracks.

I’d guess that it’s a problem with the recording system, but you’ve told us nothing about that.