Which dog barks the loudest?

All dogs have a different bark but larger dogs will probably have a deeper maybe louder bark and a smaller dog would have more of a higher pitched bark but it all depends on type of dog and age of dog.

German shepherd dog,

I have a 6 month old German Shepherd dog, he is my third GSD. He barks at 105 dB, measured by a decibel meter. The world record is 110 dB, which is held by a GSD.