The PlexTalk player, supplied by RNIB, has apparently got a switch port on the side of it.
This could be triggered by an EC system (through a relay box) to enable someone to start/stop the book if they can not operate the buttons on the device itself.
The plextalk devices do not come with IR remotes so this is probably the best option for accessing a talking book.
Control of MP3 players is possible as an alternative to talking books: