i mean rom from some controller, data are written at silicon level
i know this is tech forum, but wifi signal are electromagnetic signal while sound are vibration of a material
You can write to them too… That’s how the initial software gets onto them during the manufacturing process…
Correct. That was intended to entice people to think outside the box, hence the “scientific license”.
i found many project work on this, all failed
sound from keyboard when you press a key
how?!?
i think so, imo EM signal and audio signal are different,
if not, then we will emit EM signal when talking
imo, pressing most of keyboard key, produce the same typing sound
Unless the steps for the functioning of the device is hard-coded in the circuit design (the routing of the wires), you configure it exactly the same way you write to any electronic component that can be configured…
Yes. This can be done, but the requirements of this make it something that you wouldn’t do to simply anyone. It’s a lot of effort unless you were targeting a specific individual…
So yes. It IS possible 
the “read-only rom” i’m talking about is this
Well, ROM stands for READ-ONLY MEMORY.
I have mentored university graduates in electrical engineering, and I have never ever heard of anyone referring to the wiring of a simple electrical circuit as “read-only rom”…
https://www.sciencedirect.com/topics/computer-science/read-only-memory
i often use “read-only rom” because many people also sad “rom” (like “android custom rom”) in the meaning of “eeprom”, so i do that to avoid some confusion