How to delay an audio signal by 1 microsecond? I have an audio signal sampled at 44100Hz. I want to delay this signal by 1 microsecond (and maybe even less) for a steganographic purpose. Now if I delay it one sample, the corresponding time delay will be $\frac{1}{44100} = 2.2 \times 10^{-5}\,\text{s}$. But the delay I need is even lesser than that. How to achieve it?
It's called a "fractional delay". 

A really comprehensive analysis on how to do this can be found here: https://ieeexplore.ieee.org/document/482137/ and the design tools are still available here http://legacy.spa.aalto.fi/software/fdtools/