I recently just got a new AX5300 (RAX49S) router from Best Buy. After updating the firmware and setting it up I noticed whenever I have a device connected via wifi I hear a hissing noise coming from the router whenever sending or receiving data such as downloading a game or watching a video but not when the connected device is idle. It's only noticable if i'm withing 2 or 3 feet from the router. Strange enough I don't notice this hissing sound when using ethernet. Any idea what could be the problem and should I just see about getting it replaced?
WiFi radios can experience similar behavior especially if in a situation where it is doing airtime sharing where the device will be changing power states very rapidly (going from effectively sending out 1 watt of RF and then suddenly dropping to 0 when waiting for more air time in a more crowded environment).
Pretty much any device that does inductive loads, will have this behavior to some extent.
Years ago I remember the original Netgear R7000 had this issue, some people could hear it while older people like myself could not, it was coil whine. Graphics cards can get it and so can gaming consoles too. Sadly there is nothing you can do about it really. You could try another unit in cause this one is bad but I imagine they all have this issue.
