Narration in presentation

[Yvonne]

Hi.
I'm trying to record narration in my presentation.
Sometimes this works and sometimes it doesn't.

I'm following the correct process but the sound file icon
doesn't appear on the slide after narration and when I run
I don't hear anything. I have done all the checks and the
mic works as I have tested in sound recorder.
I managed to do this this morning and worked fine, I
deleted the sound file icon and tried to re-record but for
some reason it now doesn't work.

Any ideas why?

Thanks
Yvonne