My heart also sinks when I have to deal with a foreign accent on my land line, as I too wear a hearing aid. It is usually hit or miss, but I find that generally a female accent is easier to follow than a male one.
I recently had to phone Talk Talk ( I use them as they now are the only ones who give 24 hour free calls on land lines), I have been a customer for over 10 years). I had run out of contract and needed to negotiate a new one so the call was important to me. The 1st male I spoke to was absolutely useless and I hung up and redialled. The 2nd male was much better, I could understand him and was given a new price of £7 per month more for 18 months. When I failed to get the new contract as an E mail as promised, I rang again. This time I spoked to a female who was fantastic. I could understand her, she offered me a contract of under £30 per month over 2 years and a new fibre system which I accepted.
She was definitely head and shoulders above those 2 males I had spoken to. So sometimes I think it is a gender problem as well as an accent thing.
Another problem I had was during the pandemic, when we had to wear face masks. Being deaf, I do lip read, and I found it very difficult to understand foreign people who wore masks in a medical setting. One was in a phlebotomy clinic and the person at the door was Phillipino. I could not understand her, but she thought I was being racist, another person had to come to take my details. Another time was in a mobile Breast Test Clinic with an Asian receptionist, she too thought I was being racist. Both times I felt really embarrassed.
Another thing that has always bugged me has got nothing to do with accents, but the timbre of a person's speech. There is a male weather person on the BBC, who starts of his sentences in a normal tone, but by the end of the sentence he is practically whispering. Why this hasn't been brought to his attention, I'll never now. Thank goodness for sub-titles, although they are often a couple of sentences behind, or use goobledegook.
Anyway, I'm sorry if you think I've gone off subject, but rant over 