Worn in a pocket or harness at chest level. It consists of the body of the hearing aid containing the microphone, amplifier and controls. A cord transmits the electrical output to a receiver, which converts this signal into sound. The receiver is attached to a mould, which holds it in place.
The body of the instrument is worn behind the ear. It ‘hooks’ over the pinna. It is attached via plastic tubing to an earmould, which holds it in place in the ear.
The complete hearing aid is in the ear or ear canal. The hearing aid is housed in a hard plastic shell which is often custom made by taking an ear impression.
The hearing aid components are incorporated within a spectacle frame. It is useful for persons who require glasses along with hearing aids.
This is used when the ear canal is blocked or in cases where conventional amplification as described above cannot be given. A BC vibrator is placed on the mastoid bone behind the ear. It converts the amplified electrical signal into vibrations. BC vibrator can be used with body level, BTE or spectacle hearing aids.
Hearing aids should always be used with custom-made ear moulds. Ear moulds are devices, which couple the hearing aids to the ear. Ear moulds can be of hard or soft material.
|Types of Hearing Aids||Description||Range of approximate cost Rupees per piece as on October, 2001|
|1. Body level types||–||Rs.900/- to Rs.9900/-|
|2. Ear level types||Behind the ear (BTE)||Rs.4000/- to Rs.20,500/- (Non Programmable)|
|Spectacle Type||Rs.14,000/- To Rs.17,500/-|
|3. In the Ear||ITE (Non programmable)||Rs.8000/- to Rs.13,200/-|
|In the Canal (ITC)(Non programmable)||Rs.8500/- to Rs.20,000/-|
|Completely – In the canal (ITC)(Non programmable)||Rs.9500/- to Rs.21,000/-|
|Type of Cell||Estimated average battery life||How many per month, if used during the working hours||Approximate cost/piece|
|i. Pen torch cell (for body level aids)||100 hrs||Every week||Rs.7/-|
|ii. Button Cell||300 hrs.||Twice a month||Rs.30/- to Rs.50/-|
|a. 675 High power (mercury)||330 hrs.||–||–|
|b. 675 High power (Zn 02-Varta)||25 hrs.||–||–|
|c. 312||ITE 415 with Zinc Air 285-330||Every week||Rs.40/-|
|d. 13||288 hrs. with Zinc-Air||Every 4/5 days||Rs.40/-|