ICheap to build, wearable or at the very least very pocketable battery powered Lo-Fi (8 Khz) Digital voice recorder that Thomas Edison himself would approve of.
I'm very confident that anyone with a Atmega 328 Based board running a Arduino compatable bootloader, an old SD Card and a few junk box components can (and did) assemble a functional version of this project as a proof of concept.
There are no fancy wave shields, no made in China custom PCBS. This does not produce recordings featuring audiophile friendly frequencies only your dog or jumbo the elephant can perceive.
It will however record a .Wav file at the push of a button which can later be played back or archived.
No moving parts, no tape, no wax cylinder.