Hearing Aid components and features

Nearly all hearing aids have controls that can be adjusted by the hearing aid user. These controls can include:

• T-setting,

This feature enables the hearing aid to be used with induction loops or inductive couplers.  These are found in certain listening environments and some models of telephones, for example. For further information about the T-setting click opens a new window here.


• Volume control,

There is usually a volume control to increase or decrease the loudness of the sound. In order to save space on some small hearing aids, the volume control is sometimes combined with the on/off switch – something which also avoids the possibility of the aid being switched on at a high volume. However, some modern hearing aids have completely automatic volume adjustment, with no user control. So, if you’re buying a hearing aid, think carefully whether you would be happy with such an arrangement. 

Hearing aids are available in a variety of designs and sizes to suit different needs. And the level of amplification, volume control, and availability of additional features varies significantly between models. However, all hearing aids work in a similar way, and include the following basic parts:

• Microphone

This picks up incoming sounds from the environment and converts them into electrical signals. Some hearing aids have two microphones, enabling the hearing aid to process sounds from different areas for added benefit. These so-called ‘directional microphone’ systems, found in many modern hearing aids, can be switched from picking up sounds all around to picking up sounds coming from directly in front of you – enabling you to hear these sounds better than those coming from the side or from behind you. In a noisy environment, this can make it easier for you to focus on what you want to listen to.

• Amplifier

This takes the electrical signal coming from the microphone and amplifies it – making it larger.


• Earphone or Receiver. 

This transforms the amplified electrical signal back into sound and delivers this amplified sound to the ear of the hearing aid wearer. 


• Batteries

Like any other electronic device, a hearing aid requires a source of power in order to operate. This comes in the form of a small (usually zinc-air) battery. 


• Earmoulds

Some hearing aids need to be used with opens a new windowearmoulds – special earpieces attached to the hearing aid by a short length of clear plastic tubing. The earmould helps guide the sound from the hearing aid into the ear. If required, a good earmould is vital for the effective functioning of the hearing aid.


As well as these essential components, modern digital hearings aids include other useful features such as ‘feedback’ suppression and automatic noise reduction:
• Feedback suppression
This feature automatically reduces the whistling noise that bothers many people who use hearing aids. This whistling usually occurs as a result of sounds amplified by the hearing aid leaking back into the microphone; but a good feedback suppression system in the hearing aid can substantially reduce this problem. 
• Automatic noise reduction
People tend to speak louder in noisy environments, meaning that listening can sometimes become an uncomfortable experience. This useful feature reduces some kinds of steady background noise, like the rumble of traffic or the whirr of a fan, so that the user can concentrate more easily on people’s voices.


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