My dad is next to deaf and will not get a hearing aid. The television sound is at 80 decibels. What are the options?

TV Ears. They're wonderful. Saves everybody in the house. I use them as well, as I have hearing loss, too, and my husband has very acute hearing.

There are a few things that might help. You can try to position his chair closer to the television, turn on the closed caption to let him read the words as well, or convince him to get an assistive listening device. If he doesn't want to wear headphones, try the Audio Fox. It is a wireless speaker system that attaches to the back of his chair, and directs the sound directly to his ears.
Generally speaking, if someone doesn't want to get help, don't enable them. Tell them you are on a hearing help mission. Whenever you have to interpret something, repeat something, or turn something up, remind him "hearing help!". When he realizes how often you say it, he may be willing to get help. The trick is to do it a loving and tolerant way! Good Luck!

You can buy earphones that transmit electronically from the TV. An example, "Zone 4 in 1 wireless headphones". These aren't too expensive and will save your sanity.