Modern Usage
Acoustic tube headphones (also called pneumatic earphones or air earphones) are used especially in two-way radio. These are useful because a clear tube can be used to hide the earphones. They are also used to provide music to patients undergoing an MRI scan, as it would be dangerous to use metal wiring in the scanner's magnetic field.
Pneumatic intercoms can be applied to motorcycle helmets for pilot-passenger communication. Similar systems are common on ultralight aviation too. They are sometimes preferred over bluetooth or other radio technologies due to their simplicity and absence of batteries.
Up to the 2000s acoustic tubes were in use in some civil aircraft for movies audio and other audio broadcasting in-flight entertainments.
The principle of the speaking tube can be found on certain playground equipment, which employ tubing connecting sound horns or other speaking boxes to allow voices to travel to separate points, for the amusement of the children.
Read more about this topic: Speaking Tube
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