While driving outside Adelaide, Australia, you can find the dam of the Barossa Reservoir, built more than 100 years ago. If you walk to the end of this unassuming construction, more than 300 feet away, and speak into a certain part of it, your mate at the other end can hear you. Is it magic? No – the curved form of the dam wall bounces sound waves all along it. The wall was actually considered to be quite advanced from an engineering standpoint and was commended in the journal “Scientific American.” (Photo Source)
Curve comes into play in this acoustic phenomenon in the dome of St. Paul’s as well. More than 100 years ago, a British scientist found that two people standing on opposite ends of the dome could hear each other when talking into the wall. The sound basically can’t get obstructed because of the curved shape and Harvard University scientists used this idea to study microlasers in 2010. (Photo Source)
The Smith Memorial Arch at Philadelphia’s Memorial Hall operates like a smaller version of the Whispering Wall. It took 15 years to complete this monument to Civil War vets which features stone benches situated at its base. The benches carry sound in such a way that a person can whisper into the wall from one side of the seat to someone at the other end.
Many more amazing auditory amazements can be found at the very cool SonicWonders.com