Your spouse has a high frequency hearing loss: how to speak so you don't have to repeat yourself so much
Lower the pitch of your voice. Although it will seem unnatural at first, try talking in a lower tone. This will increase the chance of your words falling into the better hearing portion of the thresholds.
Talk at a slower pace. This will allow the listener to take a moment to "fill in" that gap in hearing.
Tap the listener on the arm before you talk. The listener can be ready to focus on your face when you speak.
Choose more words. This may seem counterintuitive, but with more words, there's more context. For example, "Where shall we eat?" is harder to understand than "Which restaurant do you want to go to?"
Use gestures whenever you can.
Don't accept "Huh?" or "What?" The listener must make an effort to help, just like you are. Instead, the listener should repeat back the portion that he or she did hear, and ask about the part not heard, like "I heard the first part of what you said, but what was the other thing you want me to buy?"