Bed 4 might have been like my late MiL. We got her a new replacement cordless phone, which had a volume control but always reverted to the middle setting after a call. So Deb showed Mom how to switch to speaker, which was loud enough for Mom. Great. Except Mom ALWAYS used the speaker from then on, regardless of circumstance, and even when she had the TV on (too loud). Made it hard to understand Mom when calling, and Deb still had to semi-yell for Mom to hear her (fortunately Deb had her own office at work by then). Alas, some people, when they find a way that “works,” keep to it, even if the way doesn’t actually so much work for others.