A loop plays, then again with one frequency cut. You find what went missing. Hearing absence is harder than hearing a boost, and it's exactly the skill you need to clean up mud, harshness and resonances without overdoing it.
Level 1 cuts 14 dB with a wide bell between 120 Hz and 8 kHz. Each level makes the cut shallower and narrower and widens the frequency range, down to a 3 dB narrow cut anywhere between 50 Hz and 16 kHz at level 10. Cuts stay a little deeper than boosts at every level, because a missing band is harder to hear than an extra one.
Your ear is drawn to what stands out, not to what's gone. A cut makes the sound thinner or duller in a way that's easy to accept as normal unless you compare carefully.
Switch between the two versions and describe what changed in words first: less body, less bite, less air. Naming the change points you to the right region before you guess a number.