pounk pounk
play music in it, me thinks.
Easy, buy a S/C.
It can be a hole in your exhaust system or it can have something to do with your engine.
It sounds like your truck has a vacuum leak. If the truck cannot build up proper vacuum pressure it will not operate properly.
Sound deadening like fatmat, or dynamat
Check the fan belt; it may need to be tightened.
You wont hear much of a sound, but more of a vibration at certain speeds. I recently installed a set of tires on my truck and because of an inbalance, around 70mph the truck would start to shake. Once I had it corrected it was smooth sailing.
Yes
the sound will get louder until you cant ignore it
As the fire truck moves away from you, the pitch of the siren would sound lower. This is because the sound waves are stretched out or lengthened due to the Doppler effect, resulting in a lower frequency of sound reaching your ears.
A big long loudHONK!
Like honk honk