Another audio Easter egg shipped in the very rare 1988 Apple Fax Modem (which is so rare that the author could only locate one fuzzy black and white photo of it). Owners of that modem could hear a digital recording of the modem’s three developers speaking their names (Peter, Alan, Neal) if they followed this formula:
While holding down the front panel button, switch on the modem. It will beep three times. After the beeps, press the button three times with the same timing/rhythm as the beeps. If you get the timing right, you’ll hear the names. (Afterwards, send me a photo of your modem, because they’re very hard to find.)