A hum or drone can come from tyre tread, uneven wear, a wheel bearing or another component. The sound can be difficult to locate from inside the car, so replacing tyres on the basis of noise alone can be an expensive guess.
Useful observations to make
Note when the noise began, whether tyres or wheels were recently changed, and whether an impact preceded it. During normal driving, you may notice a change with road surface or speed. Record those observations without carrying out deliberate manoeuvres or speed tests.
Do not weave or slalom on public roads to diagnose a bearing. A noise changing during a turn does not by itself establish which component is faulty.
Check the tyres safely
When parked safely, look for visible damage, unusual wear and anything rubbing. Check cold pressures against the vehicle instructions. Do not crawl under an unsupported vehicle or put your hand near a moving wheel.
Uneven tread can produce noise, but the cause of that wear may be an alignment or suspension issue. A new tyre may quieten the symptom while leaving the cause unresolved.
When to arrange an inspection
Have a new, persistent or worsening noise checked, especially if accompanied by vibration, pulling, heat or a warning light. Serious handling changes or visible tyre damage call for stopping safely and arranging assistance rather than continuing to diagnose the sound.
Give the garage the timing and conditions you recorded. Ask it to inspect the tyres, wheels and relevant mechanical components instead of assuming one explanation from the outset.
If the noise started after fitting
Check that the fitted products and specifications match the order, and report the change to the fitter. Tyre models can sound different on different surfaces, but a sudden problem still deserves assessment. The tyre-label noise figure describes external rolling noise, not a guarantee about cabin sound on your particular vehicle.