Summary of Hearing Aids

The form and performance of hearing aids have changed dramatically over the past hundreds of years. The first hearing aid was created in seventeenth century and in fact was just a simple ear trumpet used to amplify sounds, which was troublesome and inconvenient to use.  

The creation of both the telephone and microphone in the 1870’s and 1880’s sparked a movement towards modern hearing aids, which followed the first electric hearing aid in 1898.

Later, we were introduced to Transistor hearing aids in 1948. Transistors were more suitable and less problematic due to the facts they were small, required less battery power and had less distortion and heat than their predecessor.

Currently hearing aids are available in more styles and sizes due to miniaturization of electronics. The style you choose is dependent on the degree of hearing loss, cosmetic preference and dexterity ability. The most popular models are the behind the ear (B.T.E) hearing aid and the in the canal/ear (I.T.E) hearing aid.

The ‘social implications’ of hearing aids have changed with the transformation of the product. For example, the first electric hearing aids were very expensive as a result not accessible to all due to financial reasons. Only the upper class citizens experienced the positive implications of being able to afford this new technology.  On the contrary hearing aids now cost anywhere from $1500 to $4000 and accessible to virtually everyone in Australia. Hence positive social implications experienced include the improved quality of life as the sense of hearing is being restored or enhanced.

The materials for all hearing aids are very similar the only variable is the ear mould, which can be made out of acrylic best for low dexterity and can be manufactured with a non-allergic formula. An acrylic canal is rigid and may lead to sound leakage during chewing or other facial movement. Another option includes soft vinyl, this is the best option for active children as a knock to the ear with a hard ear mould could cause damage. Desired for their comfort and as an excellent retainer of the receiver tubing from the hearing instrument soft vinyl is very popular. Other common components that each different hearing aid shares are a microphone, mechanical switch for programing functions and volume, a battery compartment, digital or analogue processor, telecoil, receiver and an ear hook.

The B.T.E hearing aid operates in a detailed complex manner. The process begins with sound entering through the microphone alternatively this step can be replaced with the use of a telecoil, which is activated manually or comes as an automatic feature. The telecoil picks up an amplified electromagnetic signal either from compatible telephones or a hearing loop. This step is dependent on the hearing environment. Either sound submitted through the microphone or electro magnetic signals from telecoil are delivered to an analogue or digital processor where proper amplification for each individual’s prescription is changed and high frequency sound waves from background or other unwanted sounds are reduced allowing low frequency conversations to be more clear and better understood. The sound is then sent to the ear mould and delivered to the ear via the ear hook.  

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