Problems with sound after the sound system rework

After the rework of the sound system, there is a big problem with it. For example: I have droppers placed in a house. The sound of them is very loud even if I am standing 50 or 60 blocks away. There is even a wall separaring me and the droppers. When i'm walking away from them, the sound doesn't get gradually quiter. It just disappears at once.

Video demonstrating issue: Demonstration video on vimeo.com