Why is there a loud bullhorn sound coming from our plumbing?

Question

Several times a day we hear what sounds like a bullhorn coming from our plumbing. Has anyone heard of this? We were told that it was air in the line and not to worry, but it is quite loud and not going away.

Any ideas on how to get rid of it?

Answer 1

It sound as if you have 'water hammer'

Hear is an explanation from the link below

In the home water hammer often occurs when a dishwasher, washing machine, or toilet shuts off water flow, resulting in a loud bang or banging sound. A hydro pneumatic device similar in principle to a shock absorber called a 'Water Hammer Arrestor' can be installed between the water pipe and the machine which will absorb the shock and stop the banging.

http://www.answers.com/topic/water-hamme...

Answer 2

Does it happen randomly throughout the day?  Or only when you're using a sink, flushing a toilet, etc. or immediately thereafter?

When I flush my toilet, it makes a sound like the "end of the work day" whistle in the opening credits to the Flintstones.  So it sounds like you and I may have the same problem.  Unfortunately I have no idea what the cause is.