Long read but a nice story about the difference an assistance dog can make to a child with hearing loss some nice doggy pics as well https://www.hearingdogs.org.uk/helping-deaf-people/stories/zach-and-echos-story/
Been there a couple of times when I lived just up the road from the centre. Saunderton is just about half way between Wycombe and Princes Risborough and I went to a couple of open days. The work they do there is just amazing and I bet most people will have no idea that you can train dogs to help deaf people.