Wireless links can intruduce considerable latency which in turn can vary. as the wireless load varies If latency is important then don't use a wireless link!
Varying latency results is breaks in reception - the audio appears to stutter.
Ethernet cables can radiate badly, older cables moreso. Cables are identified by category, the higher category cables are better and have more shielding. If in doubt buy the best you can, CAT6 or better.