A Voice Memo refuses to play

On my iPhone 5S running iOS 8.3 I have one voice memo that refuses to play when I push "play." It is 1:21:00 in length. I can scrub along to any point in the recording, push "play," and the icon changes to "pause" but nothing happens. All other voice memos work properly. Just before trying to listen to this memo I had edited its title from "New Recording" to "Trinidad to Havana," if that has any bearing. Also, this is the only voice recording from my iPhone that I cannot find on my iMac to which the voice memos were synched. I've tried closing all open windows and I've tried restarting: same problem. Can anyone suggest how to access the recording that must surely be there?