SOUND SCIENCE
THE PHYSICS BEHIND THE EARGLASSES® HEADSET
How Earglasses® Headsets Work: The headset's reflectors are formed from a parabolic arc rotated 180° into a shape that acts as an acoustic lens. Each one is like a miniature concert shell. The arc of the lens has a focal point below the concha, the bowl at the center of your outer ear. Each reflector concentrates sounds coming from the wearer's front, and directs it into the ear. The sound retains a coherent wave form, and the proper, upright auditory image of the sound. The principles involved are so novel they were awarded a U.S. Patent, number 4,997,056.
The reflectors are so effective at magnifying sound properly because they were designed for high accuracy on mainframe computers by an IBM engineer. They are precision molded from a high impact, non-reverberant, clear plastic, and mounted on a light and adjustable stainless steel headband. The shells reflect fully 94% of the sound energy that strikes them. This includes rejecting noise which comes from sources of noise to the sides and to the back of the wearer.
For those who are interested in the technical benefits offered by this remarkably simple device, here are the details:
1. Improved Haas Precedence Effect - the direct sound from a sound source like a TV loudspeaker tends to mask the potentially distracting noise of correllated sounds ("echoes") that have been reflected and delayed by up to 30 milliseconds. Simply stated, this is the Haas Precedence Effect. But correllated sounds that travel over 35 feet, reflecting off of walls to the sides and rear of the listener, can overcome the Haas effect. This can blunt the listener's ability to perceive words, and can blur the perception of auditory source locations in listening to stereo, or live musicians. The Earglasses® headset can block out over 55% of those sound-image destroying room reflections.
2. Less Off-Axis Response - most TV sets and stereo systems' loudspeakers "flattest," most accurate frequency response is "on-axis," straight out from the speakers' fronts. Unfortunately, a loudspeaker's "off-axis" sounds make up most of a listening room's reflections. These sounds are more highly distorted as well as less dynamically accurate. Here again, by reducing the ears' acceptance of reflected sound, the Earglasses® headset can make any decent loudspeaker with good on-axis response sound much more accurate. Even a boombox can begin to evidence the listening quality of a high-end audio system.
3. Non-electronic Amplification - the shapes of the non-resonant materials used in the headsets' reflectors let them amplify sounds by over twelve decibels. This amplification is better than that produced by electronic hearing aids or amplifiers in several respects. Though not flat in frequency, its amplification frequency curve complements the losses often experienced in aging-induced hearing losses. Also, the gain is perfectly phase-coherent, and noise free. The device of course never needs batteries, or electronic repairs. The sounds which are most powerfully amplified are those which carry sounds' details, and the most delicate, easily muffled overtones.
4. Focal Adjustments - each reflector is removable and rotatable. In their fully forward positions, the reflectors can provide some hearing protection against excessive noise. Lesser adjustments forward permit users to comfortably select the best-sounding angle of focus for their listening position, relative to the performers or speakers they face.
5. Out-Of-Home Use - for those who are not self-conscious about their appearance when wearing the Earglasses® headset, they are particularly well suited to use where delicate sounds die quickly. At "packed house" musical performances, or in the thinner air of mountain altitudes, or in humid weather, instrumental overtones can lose over 25 decibels in volume just moving from the front to the rear of a concert hall. Users at lectures, plays, operas and concerts will enjoy the way that a headset reduces the distractions of audience noise, and the way performers' or lecturers' intelligibility is enhanced, even from seats in the very back row.
Caution: to prevent noise-induced hearing loss, remove the Earglasses® headset entirely and use ear plugs when in range of any noise that is loud enough to cause any degree of discomfort. While headsets can be useful for birdwatching or game tracking, they must never be worn while firing a rifle or gun. Many hearing problems urgently require professional or medical attention. Other than replacement of defective products, The Listening Institute will not be responsible for any damages or losses, including consequential damages, caused by use or misuse of its products.
