I have a hearing loss - first diagnosed when I was 25 - the doctor at the time commented, "Too many loud concerts." Which I was very proud about. But, nope, it is just genetic.
It has not become much worse over time but it is bad enough that when Connor was a pup - I encouraged him to point out things. Where is the phone? What is making that noise? That kind of thing.
At some point when he was an adolescent the realization seemed to hit him, "Holy crud, she will burn the place down because she hasn't heard the kettle whistling for the last 10 minutes."
I never had him certified as an assistance dog because I could not stand the idea of him poking me about every noise.
If I clearly react to the noise and I choose to do nothing - he does nothing. If something is going on noise related or otherwise and I have not reacted to in any way - he alerts. He whines, pokes and just bothers me till I pay attention.
And I will have to say I am the worst person to assist - when he alerts - most of the time I say, "No, I am not getting another rawhide. ENOUGH."
But he is unswervingly persistent - until I pay attention to whatever is amiss.
So, today, he is pestering me - I get annoyed - he keeps pestering me. Finally, I give in. Fine! show me what is the problem.
It turns out I left a big chunk of avocado on the edge of the table after making lunch(I was too excited about watching the horror movie and forgot). He did not eat it - he just calmly walked over and pointed out the item.
Ok, now I feel like crud. But Connor and Abby did get to enjoy avocado as a snack :-)
And no, Connor rarely if ever gets a food treat for alerting. He is just a great guy that way - he does it for the satisfaction of doing a great job.