Thanks for your reply, EIB. You confirm what I saw in my online search, that WAV seems to be a reasonably solid format for longevity. But I also saw some specs associated with it such as 96khz (I think that’s the number) and 24bit. I don’t understand how to check my recordings or what the significance of those properties is.
Also, both myself and the patient’s sister have all the recordings on our personal hard drives and backed up to our respective cloud resources. After he has died I plan to put them on a USB flash drive, too. The reason I am looking for insight into archives is that I worry about technological changes to software and hardware in the future that would make the recordings difficult to access for ordinary family members. Any thoughts about that situation? Am I over thinking this?
I suppose the most practical method would be to encourage the family as a group to make an explicitly established habit of checking the recordings at least once a year and manually transferring them to whatever suitable media becomes available in the future.
Regarding Wave Pad, I have used it and find it quite useful, even with my very awkward lack of skill. His two sisters have a plan to review and edit the recordings, and to excerpt some specific parts to transcribe for the grandson. I hope they might let me be part of that project and I can assist with the editing. But my main concern right now is preserving the original recordings in tact for as long into the future as possible.