Seamus you can also use Youtube to automatically produce captions, for free, with no need for real time playing of the interviews. See my post above.
It's not word perfect, but its not for publishing and you don't need a word perfect transcript for editing. Ten minutes of formatting and you're good to go.
Upload your interviews to Youtube. Download the captions that are automatically generated the next day. Then flick down your timeline to each question and add the time stamps into the transcript. It won't be 100% word accurate, some words will get misinterpreted, but if your audio recording is good quality it does a pretty good job. And it's free.