What To Ask Before Buying a Hearing
Aid?
How Many Different Brands and Types of Hearing Aids? There
are several different brands and types of hearing aids to choose from. No
single type of aid amplifies sound adequately for every hearing loss.
Hearing aids differ in their type of sound processing; their available
features, and in style. The most common styles include: behind-the-ear
(BTE), in-the-ear (ITE), in-the-canal (ITC) and completely-in-the-canal
(CIC) hearing aids. Each style allows for different amounts of
amplification and adjustability according to its size. For example, because
an ITC hearing aid is very small, it is less adjustable and provides only
enough amplification for milder hearing losses. BTE normally is the best in
performance and lowest in cost, but it might not be desirable for someone
since it is more visible.
Wht Do You Charge for Various Types of Hearing Aids? What is
Included in the Cost of The Hearing Aid? In
general the cost of a hearing aid depends on the sophistication and
capability of the hearing aid circuitry, and its size-the smaller the
hearing aid, the more it costs. The most expensive aids are digital and can
cost over $15,000 for one aid. More BTE hearing aids cost from $900 to
$1500 each. Usually, the biggest portion of the
cost is the selecting and fitting of a hearing aid. The cost of
this testing may not be refundable if hearing aids are returned.
Do You Offer a Trial Period During Which the Hearing Aid is
Returnable if the Patient is Not Satisfied? If So, How Long is the Trial
Period? How Much of the Cost of the Hearing Aid is Not Refunded if it is
Returned? Normally there is a trial period during which the
hearing aid is returnable. The trial period is usually 7-30 days long. If
the hearing aid is returned, many hearing aid sellers will charge a
nonrefundable "restocking fee." This nonrefundable fee could be
as little as $49 or as much as $300, depending on the seller. We do charge
19% restocking fee.
What Kind of Warranty Comes With the Hearing Aid(s)? Warranties
vary by hearing aid manufacturer. Some companies give one year free
warraty, on parts and labor. Extended warranties are also
available for an additional charge.
After the Warranty Ends, What is Minimum Charge for a
Repair? After the manufacturer's warranty has expired,
repair charges are the responsibility of the hearing aid owner. For most
hearing aid repairs there is a standard charge that covers repair on the
circuitry or electrical components. A warranty should be offered on any
repairs that are made.
You Service the Hearing Aids You Sell? What In-House Repairs
Do You Offer? We do ot repair hearing aids in-house, but
contract with Siemens or the original manufactures for their
genuine services. The manufacturers normally charges $49 to $129 for most
of the problems, plus $14 shipping.
What are the hearing Aid Terms? Although hearing aids come in all shapes and
sizes, they all have the same basic components. Sound is picked up from the
environment by a microphone. The electronic signal from the
microphone is then processed
and amplified by the hearing aid. The hearing aid volume is adjusted with a volume
control. Once the sound has been amplified,
it goes to a receiver. The receiver works like a speaker changing
electronic signals back into acoustic sound. The sound is then delivered to
the ear canal through a tube in the earmold
or hearing aid shell. Most hearing aids also include on-off switches. Some
may also have one to three screw-set controls, telephone pick-up
switch, and/or direct audio input. It commonly use the terms to specify a
hearing aid:
Saturation Sound Pressure Level [SSPL] The
SSPL [also called SSPL 90] is a measure of the maximum output of a hearing
aid, the level beyond which the hearing aid cannot amplify. It is important
that the maximum output of the hearing aid does not exceed the
Uncomfortable Loudness Level [UCL] of the hearing aid wearer. UCL is
measured in Hearing Level [HL] and hearing aids are measured in Sound
Pressure Level [SPL]. In order to convert from HL to SPL the conversion is
+20 dB [for speech only]. For example, a patient with a UCL of 90 dB HL for
speech would be uncomfortable with a hearing aid with an SSPL 90 greater
than 110 dB SPL.
Full-on Gain The
term "gain" refers to the difference between the input signal and
the output of the hearing aid. Gain is the amount of amplification provided
by the hearing aid --- how much power it adds to the environmental signal.
"Full-on" refers to the volume control setting. The full-on gain
is the maximum amount of gain that the hearing aid can generate.
Frequency Response It is assumed that the hearing
aid wearer does not use the hearing aid with the volume set to full-on. The
reference test gain [RTG] is a method of approximating the actual use
gain of the hearing aid.
Hearing aids can vary in frequency from broad band, to high frequency
emphasis, to low frequency emphasis. In order to give an idea of what the
frequency range of a hearing aid is, the High Frequency Average HFA of the
frequency response curve [obtained at RTG setting] is determined [the HFA
is the average output of 1000 Hz, 1600 Hz, and 2500 Hz].
Total Harmonic Distortion The
total harmonic distortion, or THD, of a signal is
a measurement of the harmonic distortion
present and is defined as the ratio of the sum of the powers of all
harmonic components to the power of the fundamental frequency. Lesser THD allows the
components in a loudspeaker, amplifier or microphone or other equipment to
produce a more accurate reproduction by reducing harmonics added by
electronics and audio media. A THD rating < 1% is considered to be in high-fidelity and inaudible to the human
ear.
Equivalent Input Noise The
Equivalent Input Noise is the amount of noise which is present in the
hearing aid without any input present. The electronic current passing
through the amplification system of the hearing aid will cause a low level
of noise. Higher gain instruments tend to have more input noise. This is
not usually a problem because the wearer of such a high gain hearing instrument
will not hear the noise. Ambient noise present in any room is usually
enough to cover any noise generated by the hearing aid circuit. Typically
the equivalent input noise is less than 3--35 dB SPL.
Battery Current
The battery current of different hearing aids can vary
widely. It is important to have an estimate of battery current so that the
hearing aid battery life can be predicted. Battery current is tested with
the volume control in reference test gain position and with an input of
1000 Hz tone at 65 dB SPL. Often the hearing aid test equipment will have a
"battery pill" which draws current from the hearing aid. Battery
current values can range from 0.2 mA
[ milliAmps ] to 5.0 mA and can
be as high as 15-20 mA for body style hearing aids.
Other Hearing Aid Parameters
All hearing aids are tested with the above requirements.
In addition to these, any hearing aid with a telephone telecoil
can have telecoil frequency response
measured. Also, automatic gain control [AGC] hearing aids require testing
of the input-output characteristics and attack/release times.
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