If I had a secretary to transcribe voice notes I'd do it too. But having used a tape recorder - as sparingly as possible - in the past as a journalist, I know the limitations of that machine for my purposes. It's just one more step between me and the information I need.
I prefer to jot notes on my contact sheets and work prints. Typically, date, paper type, enlarger lens, exposure and contrast settings, burn/dodge info or diagrams, etc.
If there was a way to use voice technology that fed oral notes directly into a computer database, I'd consider it. In fact, the technology probably exists now - but there's no room in my darkroom for yet another bit of gear.