(-1.5 db ) is about the first significant notch of audible change variant that folks notice. So sometimes when people want things down "a little" or a "hair" it could mean (-6db) or more, depending on how sensitive they are to the change, how loud they're listening, their relative perspective on life, family history, balance of power at home, body mass index etc...
When discussing audio feedback via email sometimes phone/laptop listeners work well with percentage % increase or decrease terms rather than the audio meter (+/- db) nonsense that I'm used to dealing with. So if the starting point of something in question always equals 100% , then up or down X(%) based on that is sometimes easier to translate.
Client: "Turn up my guitar solo 10%"
Operator "10% of what ?""
Client "10% more of what's already there."
Operator "Oh, sure... makes sense. You are 100% correct, per usual"
Numbers don't lie.