I get woken up once a week by a sound similar to the one the Golden Gate Bridge is making. It starts around 4am, except it comes in short pulses. I recently fig

I get woken up once a week by a sound similar to the one the Golden Gate Bridge is making. It starts around 4am, except it comes in short pulses. I recently figured out it was the breaks on the garbage truck that services my neighbourhood. They make a really loud high pitch hum every time it stops, and when the truck isn’t particularly close by, you can’t hear the rest of the truck sounds, but you can hear that hum very loudly. The local council didn’t really care when I told them. It doesn’t bother me too much because I get up quite early anyhow, but I imagine this truck would manage to bother a rather large number of people every week. I wonder if the sound will go away next time it’s serviced.