I'm a professional audio engineer and technician. I'm truly an audio geek.

I think the level of dB's a person can tolerate is of personal taste.

When I had the iicp, a soft whisper brought me lots of pain. Now, I'm good around 125dB again, but the content might make aggravate and degrade my cognitive functioning - but I'm pleased to report that it's still improving.

You might like this little chart:

http://www.gcaudio.com/resources/howtos/loudness.html

And whomever you spoke to at your church is correct: 80dB is quite low for a service for a large church. But I do wonder who's measuring it, with what instruments and from what location: because each of those answers can affect the outcome of the measurement. But they're probably not too far off with their estimation (I hope.)

Edited to delete the measured dB at the church I volunteered at due to memory recall dysfunction.