For a couple of years I've been listening more to audio books and podcasts when painting soldiers and building models. This way I can get two things done at once. I think I'm probably actively listening about 80% of the time but after an hour or so the mind can still drift - mine anyway. Over the past weekend I've been accessing a Conan adventure through YouTube. But here's the thing ...
The speaker is the all important ingredient and sometimes I just can't hack it (no Conan pun intended). If the accent is too powerful and mismatched then it destroys the feel for me. For example, I'm an Australian with what might generally be referred to as a 'received' accent - other Australians pick up that I spent some time in England (Kent) during my childhood. If you watch the Australian Broadcasting Commission (ABC) newsreaders then that's the sort of accent I have. So, when I'm listening to a similar voice or someone from certain regions in the UK, I barely register there's an accent at all because it's largely my own.
I generally find broad English or American accents need to be relevant to the subject matter. So, (for me) a range of distinct northern English accents are going to be fine in an English historical context and a strong American accent fits in perfectly for American military subject matter. What I can't take is a broad Californian speaker delivering Shakespeare or a Scotsman reading an account of Custer's Last Stand.
There are two other problems for me with many audio readers. The first is intonation or how dynamic the reader is. Some of them are so very, very, very monotone. They are boring and they put me to sleep. The other problem is the single reader's inability to impersonate. The Conan adventure I was listening to has a cast of characters, male and female but the reader I had (an American) only had one 'other' male voice and one female voice when switching from narrative to dialogue. This is both amusing and confusing. Some readers have truly silly female voices akin to Terry Jones standard 'woman' screeching SPAM, SPAM and when there's a romantic exchange like in the Sharpe novels, it's just wrong!
Most of my audio book collection is non-fiction historical narrative anyway so provided the reader is good, characterization is relatively unimportant. I really do think that the audio book recording industry as a whole needs to consider multiple readers and audio editing to raise the bar. I'd actually like to see (hear actually) novels presented more like radio plays with sound affects and voice performers. It would engage the listener completely and I could get lost in other worlds whilst painting my soldiers.