Captel "lets you keep in touch" with your loved ones.  You've been refused all other communications services for the hearing impaired. The all powerful Captel is being magnanimous by "letting" you keep in touch if you use their service?  Yeah, right!  Like...ever heard of texting?

How about Captel "helps you"?  I'm sure that's true.  It seems like a good idea.  But they don't control all communications.  "Let" would be okay if it's a new feature for your existing landline phone--which it may be.  But then say "lets you use your regular phone" rather than lets you keep in touch.  Isn't the tone of "helps you" much friendlier, anyway?