What Causes This Sound?

There is this weird sound that happens when there’s nothing playing on the stereo. I can even hear it when the volume is all the way down.

You should post this in UFO subreddits and see what they think.

Mine does that too when it’s in Bluetooth mode and the radio volume is all the way down. Seems like it’s radio interference.

Blaise said:
Rain.

:joy: Indeed! I was curious about why there was sky water.

(I hope you’re aware I was referring to the sound)

Zaren said:

Blaise said:
Rain.

:joy: Indeed! I was curious about why there was sky water.

(I hope you’re aware I was referring to the sound)

Could be a sprinkler. Maybe the neighbor washed their car.

@Kai
'Round here, that would just make mud.

Zaren said:

Blaise said:
Rain.

:joy: Indeed! I was curious about why there was sky water.

(I hope you’re aware I was referring to the sound)

You’re welcome, OP.

Haze said:
What causes rain?

Read the caption?

Electrical feedback; this happens when the ground is not properly connected.

Luca said:
Electrical feedback; this happens when the ground is not properly connected.

Not always just a ground issue; other wires/modules can induce current in different wires/modules/speakers, which is what you’re hearing. It can be due to bad grounds, but that’s not the only cause.

I don’t know, mine does this too.

Head units sometimes do this if they don’t have an isolated ground to the battery. LED lights can cause interference as they’re not a proper resistive circuit, leading to a ‘short’ (though it’s not literally a short—LEDs have little to no resistance). Thus, you’re likely experiencing some backfeeding into the chassis. This can create static in your speakers, even when the head unit is off.

If you don’t have LED lights, I’d suspect there’s backfeeding internally from the head unit.

@Robin
No LEDs for me. It’s a 2014 1.5L SE.

Could be communication from remote impact sensors. Most of them use PWM communication from the sensor to the main airbag control ECU.