Whatever happened to those weird noises affecting nearby speakers when we received a call on a cell phone back in the days, as illustrated in the link?

Question

https://streamable.com/yerb9

I was appreciating the nice little attention to that detail in gta4, but it got me wondering how come it’s gone nowadays.

In: Engineering

Answer 1

The cell phone transmits quite a bit of RF energy when it is talking to the tower. That energy can leak into the amplifiers in a stereo system and disturb their operation, creating the sound you hear.

I don’t know exactly what happened, but I would guess they fixed this issue by:

– shielding the stereo amplifiers better (metal box)

– adding RF filters to the amplifier inputs

– making opamps with better RF rejection (basically built-in filters)

Something like the above. I would also hazard a guess that there are probably a lot of stereos floating around where this still isn’t fixed.