Or are they the directional ones you were referring to?
One of the features that the app can control is the "environment". When out and about it's set to omnidirectional so that someone next to him doesn't need to be talking directly to him, however that picks up a lot of background and when in a building that causes.
He's also wired up their house with an audio loop. There's a microphone at my mother's craft desk that goes directly to the hearing loop and he can hear it anywhere in the main rooms of the house.
However, going out to places where he needs to be able to talk to people with less assistive technology available, things like the dictation mode on the phone area used. Also, sometimes he'll miss words (the start of a sentence until he realizes someone is talking to him, turns his head and the directional hearing aid mode gets them in focus). Being able to review the last 15 seconds of what was said on his iWatch would a technology that he would use.