Does audio upsampling create noise/artifacts or degrade the signal?

1. Does upsampling affect audio quality?
2. What happens when an audio is Upsampled?
3. Does upsampling cause distortion?
4. Is it better to downsample or upsample?

Does upsampling affect audio quality?

When we upsample a 44.1kHz 16-bit file to a higher rate and depth, like 96kHz 24 bits, we typically get better sound quality. And since the magic of upsampling just sort of works at the touch of a button, we seem to be getting more for nothing. After all, the file size is considerably bigger.

What happens when an audio is Upsampled?

Upsampling is the process of inserting zero-valued samples between original samples to increase the sampling rate. (This is sometimes called “zero-stuffing”.) This kind of upsampling adds undesired spectral images to the original signal, which are centered on multiples of the original sampling rate.

Does upsampling cause distortion?

Distortion during upsampling is called imaging. It means creation of frequency components above 1/2 sampling rate of the original signal. Sometimes it is also considered to be a form of aliasing.

Is it better to downsample or upsample?

It depends on the level of certainty you need. If you don't need mathematical certainty and just want a heuristic, downsampling is faster and upsampling is more accurate.