Work in Progress! Pictures to come.
I traded in my 2017 Toyota Prius V for a shiny new Prius Prime Limited because I now work from home and 98% of my driving is in range of the EV mode. The major problem I have with it is that the pedestrian alert whine from the AVAS (Acoustic Vehicle Alerting System) is substantially louder inside the car than it was in the 2017. And the sound it makes is far more abrasive (to me) as well; so much so that I cannot drive it below 22 MPH without the radio up fairly loud to drown it out; otherwise it makes my teeth itch (yes that is really a thing), and triggers pretty severe headaches.
What’s a car owner to do? For starters, I needed to identify where the noise maker is located. That, thankfully, was not hard. If you open the hood, there is a black plastic cover along the very front of the engine compartment that covers up the fans. It is held on by little plastic panel pins, which are easy enough to pop out with a plastic pin remover (or, if you must, a screw driver, but be careful not to damage them). Word of caution here: When you pop them out, pull the whole pin assembly out and set it aside as you work down the line. I mistakenly thought they would stay in their holes, and two of them popped into the engine compartment black hole, never to be seen again (at least without jacking/lifting the car up to remove the bottom engine compartment shield. The message here; don’t drop anything in the engine compartment you want back easily.
Now that you have removed the cover, you can see the speaker assembly. It is in the space that removing the cover revealed, right in front of the pink coolant tank. You will need a 12mm socket to remove it. Same warning about dropping the bolt.
You can verify you got the right device by checking the part number: 86570-12030
The speaker was designed to be very hard to defeat. There are openings all around it. I put electrical tape over all the openings, and that lowered the volume of the sound dramatically. But still not enough to avoid headaches without the radio on.
So what is another option? Unplugging it will cause a fault light on the dash until it is reconnected, so that in and of itself is not a solution. However, it is just a speaker. A speaker is just a resistor. So, we should be able to just replace it with a resistor. Based on a Prius Chat Forum post, a >= 5watt, 8-10 ohm resistor should work.