Hearing Aid Operation
Hearing Aid Batteries
Every hearing aid uses batteries of a specific size and number. The batteries can be made by any manufacturer, but must be the correct size. For example, #675 is the one most commonly used in "behind-the-ear - type hearing aids, #13 can be used for smaller "behind-the ear" and in most "in-the-ear" - type aids.
There is a positive and negative pole or end with each battery. The positive end is marked with a little (+) sign. The (+) sign on the battery must be placed in the aid on the same side as the (+) sign indication on the battery door (i.e. battery will last longer and leakage or corrosion of the battery is prevented if not worn for a long time). When the battery is dying or losing its charge, it may go weaker gradually or suddenly "cut-out".
There are two types of batteries: mercury and air activated. You may find it helpful to try both to determine which lasts longer and suits you better. It is generally found that mercury batteries are less expensive but do not last as long. If they have been lying on a store shelf for a while they might not last at all. It is important to purchase your batteries either from your hearing aid dispenser or a store which has a reputation of discarding batteries which have been on the shelf for a long time. In order to use the Zinc Air batteries the sticky tab attached must be removed. This allows air to pass into the battery and activate it.
Care of Hearing Aids
Hearing aids are carefully designed and built according to the physical and hearing characteristics of the individual ear. They represent the highest hearing technology available and a significant investment of time and money on the part of the purchaser.
The earmould is an essential feature of the hearing aid system. It provides support for the aid and directs the amplified sound into the ear canal with high efficiency - if it fits properly. If it does not fit properly it may cause whistles and squeals, or produce local irritation and soreness. Ready-made earmoulds are available, but for a good fit, it is worth the expense to have a mould custom-made to the exact shape of your ear.
General Points on Hearing Aid Care
A user booklet accompanies each hearing aid when it is sold. This booklet should be kept where it can be referred to for information regarding battery insertion, type of battery and proper use of controls.
Along with each ITE purchased, the buyer should receive a small tool for removing ear wax from the earmould canal. This tool is a slender rod, about 5 cm. long, with a tiny brush at one end and a small wire hoop at the other. It often also has a tiny magnet shaped like a round dot on one side near the end, which is helpful in removing the battery from its compartment on the aid.
Hearing Aid Controls
ITE's have an on-off volume control. A telephone "T" switch is available as an option on most hearing aids, but not canal aids. Some practice may be necessary to learn to use the T switch effectively. The on-off switch is part of the volume control on most hearing aids, but there are certain models which require opening the battery compartment to turn the unit off. Whenever in doubt, open the battery compartment or remove the battery to ensure the hearing aid is "off". The volume of the hearing aid is controlled by placing the tip (pad) of a finger or thumb on the control and rotating it forward for louder and backward for softer. Try to find a loudness level which is most comfortable, yet sufficiently loud to hear and understand clearly. Some ITEs have a raised dial for increased sensitivity to aged fingers.
Battery Insertion
Batteries which are inserted improperly will prevent the hearing aid from working and can cause physical damage to the unit. The smallness of in-the-ear hearing aids may cause difficulty in seeing battery markings and compartment markings. A magnifying glass and good lighting is a help.
Cleaning
Be sure to work on a table or other hard surface. Use a soft tissue to wipe the hearing aid clean. Do not use water or solvents which may cause damage to the unit. Wax buildup or blockage may be removed with the wire loop tool or brush which comes with your hearing aid. If using a wire loop, gently insert the loop into the sound canal opening and pick out the debris.
Be careful to not pick at the tube which lines the opening. If this is pulled out, the hearing aid may need to be returned for repair. If using small brush, turn the aid upside down and brush out the wax so it falls out on the table.
Earmoulds
If in the first year an ITE earmould loses fit, the dispenser will redo the earmould. Some dispensers have recommended purchase of a new ITE, if there is a problem with earmould fit after two years. However, more recently in many cases, a new coating of material can be applied to the earmould, to again provide a proper fit. With this solution, more ITE users report that they are wearing the same ITE aid for five to six years.
Hearing Aid Controls
There are no standards for indicating control functions, so the same symbol may have a different meaning from one brand to another. A variety of switches are also used. The most common switch includes: on (M), telephone (T), and off (O), followed by on, off, tone switch (MH), MO). Separate on-off switches are seen in older hearing aids. Certain instruments have an on-off switch included on the volume control. A slight click is noted when the volume control is turned all the way down into the off position. The battery compartment must be opened or partially opened to turn other hearing aids off.
| Symbols | Meaning |
|---|---|
| M, + | ON |
| O, -, Off | OFF |
| T, MT | TELEPHONE |
| M, , Hz, S, T | TONE SWITCH (on) |
When markings and control functions are unclear, a hearing aid may be turned off by removing the battery.
Noise Supression Switch
This position reduces low tones or frequencies which are responsible for background noises. Many hearing aid users prefer the sound of their hearing aid in this position because of the noise reduction and higher pitch of the sound.