Open-Ear Hearing Aids
One of the historic problems with hearing aids is how to appropriately amplify high pitches without overamplifying low pitches. High pitches give clarity to speech, low pitches provide loudness (bass). Most sensorineural hearing losses are worse in the high pitches than in the low pitches. That is why people with this type of hearing loss complain that they hear but do not understand what people are saying. Amplifying the high pitches without amplifying the low pitches has been a problem plaguing audiologists for years.
The problem stems from making the most of the high pitches, so that speech can be better understood, without occluding the ear canal. When the ear canal is blocked, similar to putting a finger in your ear, internal sounds, chewing, swallowing, and even breathing, are louder. If there is normal hearing in the low pitches, these sounds can be intolerable. If this effect occurs from a hearing aid in the ear, that hearing aid may be rejected.
The traditional remedy to this situation is to open a vent for the low pitches. This solution frequently solves the problem. However, with some people, this remedy opens the way for acoustic feedback. High pitches are the ones that ring or feedback; thus, the dilemma.
In 2004, GN Resound, an international hearing aid manufacturer, introduced a new type of hearing aid, called AIR. This hearing instrument allows for maximum highfrequency amplification, with less possibility of acoustic feedback. The device itself fits behind the ear and a narrow bent tube passes over the ear to an eartip, which fits in the ear channel.
The difference between this
instrument and traditional behind
the-ear hearing aids is size and shape. The AIR hearing aid is less than half the size of traditional behindtheear hearing aids. It uses a size 10 battery, which is one of the smallest hearing aid batteries. The size of the tubing attaching the hearing aid to the ear, is much thinner than traditional earmold tubing.
This serves two purposes high pitches are less likely to feedback, and the tubing is almost invisible on the ear. In addition, there is no need to make an ear impression with this hearing device. Eartips of varying sizes are attached to the end of the tubing, instead of the traditional earmold.
The process of fitting this device is simplified, because it is not custommade, nor is the eartip, and the AIR is digital and programmable, making easy inoffice fitting and modification.
What are the disadvantages of the openear fitting? This type of hearing device is only appropriate for highpitched hearing losses. Those with severe hearing loss, or a need for amplification in the low pitches, are not considered candidates for openear