I've always liked the fact that when you plug headphones into the headphone jack of my laptop, the laptop will not make a sound. For example, if I'm in a class and I need to restart my computer, I'll first reach into my bag, pull out the 3.5mm plug end of my headphones, and stick it in the computer. This prevents any boot sounds from going off, which inevitably happen at full volume and don't respond to the hardware mute button.
Rather than using headphones, I've been wondering if there is any device made for this purpose. I imagine a little 3.5mm jack which sticks out of the computer a tiny bit when plugged in (just enough for you to pull it out), something which can stay in the computer.
Does such a thing exist?