Most of these “tester” positions are boring to the point of testing your sanity. Monotony is the state of doing little outside of a simple, repetitive routine and it offers a unique hell to each of its occupants. When one is consumed by tedium, they are compelled to consume it in turn, reshaping themselves to fill their fresh wounds like a reluctant ouroboros. You dip, you walk, you place, you return, you dip, you walk, you place, you return. The shining isn’t far off.
Honestly, if it paid well enough and I were to lose my current job, I’d live to be in this sort of job. Life’s too short to be stressed about work. Just go, do job, get paid, and live my life.
It sounds like you've left the field, but I'll never miss a chance to proselytize bone conduction headphones. Mediocre sound quality, but they leave your ears completely open and can work through ear protection.