This is just a link and not an own project of mine. But, it fits right in here and is at the same time useful and hilarious. So, here it goes, the latest article from Low Tech Magazine:
“Non-Electric Hearing Aids Outperform Modern Devices”
Money quote:
“Since the nineteenth century, the main criterium for a hearing aid is no longer its effectivity but its discretion and compactness. Nevertheless, those who can overcome their vanity can revert to technology that has proven to work.”