Forklifts: How Loud Are the Back-Up Alarm Beeps? Can They Worsen Tinnitus?

Preface:

I tried doing a search and those loud back-up beeps can apparently get quite loud and possibly up to 100 decibels. But how close to the source would that be? And how about the volume of the forklifts themselves? I'd imagine we have some current or former warehouse workers who have been around them.

The issue:

I've started to exercise at a place where they are sharing warehouse space in the back of a large market and to my frustration this afternoon there were a couple guys the entire time moving stuff around on forklifts. It was maybe around 20 feet away. I perceived it to be loud enough that it was really messing with my focus and I wanted to leave because of it, but I pay for these sessions and so I don't want to just get up and go.

Exposure time:

The guys were using the forklift for around an hour and I was about 20 feet away. Concrete floors and so it's also very echo-y in there. I'm assuming the back-up alarm (beeping) is much louder than the forklift itself, but I'm not sure. The beeping was every few seconds and the forklifts were operation the entire time.

Would this be a cause of concern? I did not have earplugs.