Novel device may protect people from ‘listener fatigue’

Washington, May 14: Engineers investigating "listener fatigue" have not only found the possible cause, but what they believe is a potential solution too.

"Listener fatigue" refers to the discomfort and pain some people experience while using in-ear headphones, hearing aids, and other devices that seal the ear canal from external sound.

Stephen Ambrose, Robert Schulein and Samuel Gido of Asius Technologies of Longmont, Colo., described how sealing a speaker in the ear canal dramatically boosts sound pressures and how a modified ear-tip can help alleviate, or even eliminate, that effect.

Using physical and computational models, the researchers show that sound waves entering a sealed ear canal create an oscillating pressure chamber that can produce a potentially dramatic boost in sound pressure levels.

To counter the oscillations, Ambrose and his colleagues developed a way to use a membrane outside the eardrum to take the brunt of all the pounding. This "sacrificial membrane" disrupts the excessive pressure waves, protecting the eardrum and preventing the triggering of the acoustic reflex, ultimately leading to lower, safer listening volumes.

"From the beginning, I knew something would have to be done about this audio fatigue factor," said Ambrose, though he had trouble proving that pressures were so extreme.

"I invented the diaphonic pump partly to prove that audio volumes could create static pressures in the ear that no one ever dreamed were possible," added Ambrose.

The discovery was detailed at the 130th Audio Engineering Society convention in London.

Copyright Asian News International/