Yep you read that correctly. The tic-toc blinker sound is there for you, and not required for the turn signal to actually work. How do I know this? Well as of late, my truck has had a weird quirk whereby all audio doesn't work when starting it on a very cold morning. And I do mean ALL audio. So Bluetooth, radio, and yes the blinkers were strangely silent.
Lets recap that sound. So historically cars have used what's called a Turn Signal Flasher Relay which is a very simple device. It essentially is a thermal spring that heats and cools quickly to make the connection back and forth switching the voltage between the front and back lights. This tried and true design have been a staple of under dash electricity routing for many years. The downside is that they had a habit of failing now and then, even though they are very easily replaceable. In fact I recall carrying a spare in my glove box along with fuses.
Recently, however, and I'm not even sure how long this has been so, but now flasher relays are solid state electronics. Cheaper to make, more reliable, and yes silent. So apparently what's happened is the car makers decided that we the consumers like that clicking noise and started simulating it and in the case of the 2015 Chevrolet, its a part of the audio system.
