I am a sound recording engineer. I was quite surprised, when I was playing with Buster and one of his squeaky toys, at how loud the squeak actually was! So surprised that I brought it into work and measured it's loudness with a Sound Pressure Level meter. This toy was putting out a a huge 106-104 db SPL (decibels of sound pressure levels) I looked it up in the charts according to them the permissible exposure time for continuous time weighted average noise is under 4 minutes.
This is a chewing toy and therefore the squeak is right up at his ear when he plays with it. I wonder if one of the causes of dogs going deaf is the exposure to that loud of a sound over the course of their lives. Honestly I was quite shocked by how loud it actually was. I am going to have to go through all of Buster's toys now to check out how loud they are!
Dangerous Decibels How Loud is Too Loud?