Harman and Dr. Sean Olive are reshaping headphone sound (2025)

Well, the dB scale was once created on the basis that 1dB was thought to be the "just noticeable difference". Off the top of my head, I think trained listeners can actually notice differences of 0.3 dB, though this sort of thing is going to be frequency dependent too.

The eq-adjustments you'll find online often have adjustments ranging from 1 to 6dB in different frequencies. That's enough to notice.

Comparing settings/devices, it's very easy to notice. Just play some music on your laptop/phone speakers and move the device around a bit, and you'll hear striking differences in highs and lows.

However in isolation, I think most people wouldn't be able to say if a particular sound source is "good" or "bad". It takes a while for you to clock that, no, it's not the teams/zoom call that has bad quality, it's your headset that's dropping mids.