I have to disagree, in my case my hearing got significantly better since I started using tuners.
Today I noticed that the old fridge rattles in low G. Maybe I should use it.
So no one else here used dial tone in the 70's? I didn't even know electronic tuning devices existed in the 70's.
I got my first tuner in '83, in fact I still have it somewhere, it was called a Banana tuner. Bought it in Philly the same day I got my Arbor brand Explorer-style bass ($90) and Reebok high tops... remember when you just had to have them?