I found a free, online service that provides speech-to-text transcription, and also enables one to search for a particular audio string. In this case, I had a great audio recording that I ad-libbed as I captured video of software, without a script. (It was a very creative but not careful day .) Now I have better recording equipment and need a transcription so I can record again.
You might also have a case where you need an after-the-fact script of another person's recording, such as a speech. You might also need to search for a particular audio string. And since it's an online repository, you could use this service as a backup audio archive.
Here's the link. Although the basic, free transcription is machine-based, and therefore imperfect, they also offer a fee-based, human transcription.