All laptops with a 5 kHz tone would be returned as defective. In the 90's harddrives often had a 7200 Hz whine which was enourmously annoying. Todays harddrives are silent compared to the old ones.
But whether anything is bothered by the sound depends on the energy level and other characteristics. Spread spectrum ultrasound sonar below the local noise floor may be technically feasible, though perhaps not with regular laptop speakers and audio circuitry.
I'm unlucky enough to hear 15 kHz, and you'd easily hear any TVs turned on two storeys away. CRT ultrasounds used to be unbearably, migraine-inducing loud.
I assume laptop speakers wouldn't be anywhere as bad.
The what now ? nothing in hard drive runs at that frequency