03 - Hearing Aids 1
We know hearing aid technology has come along way. What are some of the more recent improvements?
Advanced circuit design -chip designed to process sound Digital/programmable Probe mic verification -Stick a tiny mic in the canal and you can verify by a third-party More functions Smaller Better sound quality More reliable Connectivity -Bluetooth streaming to your phone
Just NAME the types of HA STYLES:
Body Aid Eyeglass Aid BTE Hearing Aid ITE Hearing Aid ITC Hearing Aid CIC Hearing Aid Bone Conduction hearing aid Implantable hearing aid
What are some advantages to completely in the canal styled hearing aids?
Cosmetic appeal Completely in the canal and pulls out with a thread Less wind noise Better for high frequency amplification due to: - Microphone location - No obstruction in the concha
What are some disadvantages to the behind the ear hearing aid?
Cosmetic concerns Wind noise
What are some benefits to implantable hearing aids?
Eliminates pressure buildup, feedback and distortion
What does the The Earmold for Behind the-Ear HA do?
Function: deliver sounds from a HA to the ear canal Composition: the mold and the tubing Comes in many different styles, sizes, and materials (silicone, acrylic)
Info of the SPEAKER/RECEIVER
Is an output transducer In general, larger receivers can supply louder output signals Is vulnerable to damage from ear wax Is vulnerable to moisture
What are some DISADVANTAGES to the In the Ear (ITE) and in the Canal (ITC) style HA?
Less fitting range, not suitable for severe hearing loss Wax problems More prone to feedback`
What is the BTE styled HA?
Microphone, amplifier, and speaker are located in a small case that is worn behind the ear Sounds are delivered to the ear via a tube and an earmold Fit all types and levels of hearing loss Advantages: Most powerful Wide frequency response Less feedback noise Easy to handle More options Disadvantages: Cosmetic concerns Wind noise
We know the basic components of the hearing aid include the microphone, amplifier, speaker/receiver, and battery. Explain what each does:
Microphone: -Pick up sound from environment and convert acoustic energy to electrical energy Amplifier: - Increase the amplification of the electronic/digital signals Speaker (receiver): -Convert electrical signals to acoustic signals Battery: - Last for 3-4 days to 3-4 weeks depend on the size of the battery and the duration of everyday usage. - Come in different sizes with the same voltage: 1.45 v
What are some common problems with implantable hearing aids?
Needs surgery to implant the device Needs a body part Has to be removed if MRI is needed
For hearing aids, what is the difference between the Omni directional microphone and a directional microphone?
Omni-directional microphone: -Pick up sounds from ALL directions Directional microphone technology: - Conventional directional microphone - Dual microphones - Microphone array
What are some setting options for hearing aids?
On-off switch- must request now, not found on most HAs - M (microphone), O (off), T (telecoil) - Closing/opening the battery door Volume control: - Most digital HAs do not need it (Because the hearing aid does all the adjustments automatically) - Experienced HA users often prefer it Program switch: - Select program to meet the differing listening conditions Remote control
Venting for HA: What's the function and what are some potential problems?
Present in almost all HAs Function: - Reduces low freq (500 Hz and lower) gain - Reduces the occlusion effect - Minimizes moisture buildup between mold and ear drum Problem: - Can cause feedback, which can be corrected by adding a vent plug or narrowing the vent diameter
How do you Describe an Audiogram (Hearing Loss)?
The description of a HL should include: - Lateralization: *symmetric vs. asymmetric *Or bilateral vs. unilateral Degrees: mild, moderate... Configuration: flat, sloping Types: Sensorineural, conductive or mixed HL
We know the difference between the Omni directional microphone which picks up sound from all directions, and the directional microphone. What are the IDEAL CONDITIONS for DIRECTIONAL technology?
The noise originates from behind the HA user The speaker is in front of the HA user The HA user is close to the speaker The room has low reverberation (echoes)
We know there are phone options for hearing aids. Explain the Telecoil (T coil):
Used for connecting directly to phone Responds to magnetic fields rather than sounds Usually controlled by a switch Limitation: blank spots due to the unevenly distributed magnet field
What are some program options for hearing aids?
Varies by level of technology and manufacturer: Master/standard Comfort/restaurant Music TV Tinnitus sound therapy Phone options
We know the basic components of the hearing aid include the microphone, amplifier, speaker/receiver, and battery. What does the AMPLIFIER do?
- Increase the amplification of the electronic/digital signals
We know the basic components of the hearing aid include the microphone, amplifier, speaker/receiver, and battery. What does the BATTERY do?
- Last for 3-4 days to 3-4 weeks depend on the size of the battery and the duration of everyday usage. - Come in different sizes with the same voltage: 1.45 v
We know the basic components of the hearing aid include the microphone, amplifier, speaker/receiver, and battery. What does the SPEAKER do?
-Convert electrical signals to acoustic signals
We know the basic components of the hearing aid include the microphone, amplifier, speaker/receiver, and battery. What does the MICROPHONE do?
-Pick up sound from environment and convert acoustic energy to electrical energy *it has a high impedance-resistance component So it blocks out sounds like wind
We know the AMPLIFIER increases and strengthens the signal. What are some Technological advances:
1. Conventional - already gone An analog circuit: can not be adjusted Without dynamic compression 2. Programmable - already gone An analog circuit: can be adjusted, but the flexibility is limited 3. Digital - all hearing aids are now digital technology
Amplifier: Digital hearing aids have a sound processor. What does it do?
Monitors input sounds before amplifying them Automatically adjustable More frequency channels More functions
What type of hearing aid is ideal for a patient with mild to moderate specifically high-frequency hearing loss
Open fit BTE
Name some common problems with bone conduction hearing aids?
Pressure on the bone cause discomfort Loss of the sensation of sound localization
There's some common problems with completely in the canal styled hearing aids?
Problems: Susceptible to damage (2-3 times more damage) and expense to repair Short battery life Easy to be blocked by ear wax Difficult to handle Less fitting range More expensive
What are some ADVANTAGES to the In the Ear (ITE) and in the Canal (ITC) style HA?
Reduce the cosmetic concern Fit more securely in the ear than a BTE
The Electroacoustic Properties of Hearing Aids include gain, output, max power output (mpo), distortion, and equivalent noise. Explain EQUIVALENT NOISE
The amount of noise produced when there is no input signal
The Electroacoustic Properties of Hearing Aids include gain, output, max power output (mpo), distortion, and equivalent noise. Explain DISTORTION
The amount of unwanted signals or noise amplified
The Electroacoustic Properties of Hearing Aids include gain, output, max power output (mpo), distortion, and equivalent noise. Explain MAXIMUM POWER OUTPUT (MPO)
The maximum possible acoustic output of a HA
The Electroacoustic Properties of Hearing Aids include gain, output, max power output (mpo), distortion, and equivalent noise. Explain OUTPUT
The total amount of sound that a HA can produce: Gain + Input (dB SPL) = Output
This is what Normal hearing right ear, mild to moderate sloping sensorineural hearing loss above 1 kHz in the left ear looks like...
They would benefit from a smaller hearing aid and Max venting with no earmold
This is what Bilateral mild to moderate flat conductive hearing loss looks like
This is a conductive loss with occlusion, closed
True or false: most behind the ear hearing aids have an FM system option which is important for school settings
True
What is the definition of a transducer?
Turning info from one form to another
Explain the Bone Conduction HA
Used in patients with: Chronically draining ear Malformation of the middle/external ear (ie. microtia) Bilateral conductive loss due to ossicular disease who are not appropriate for surgical correction and are unable to be aided by a conventional air conduction device.
What is the BODY AID styled HA?
Used in patients with: very severe hearing loss severe visual or handling problem Problems: cosmetic concerns wire breaks inconvenience body buffing noise from clothing directional hearing
About how many years can you get out of the hearing aid on average?
You can get about 5 years out of the hearing aid
What level of hearing loss is ideal for the BTE hearing aid?
all types and levels of hearing loss
Hearing Aid History: The first ever hearing aid was called a _____ _____ And it did not amplify sound correctly. Instead everything sounded just plain LOUD
body aids
Percentage of individuals who NEED hearing aids actually WEAR hearing aids?
only 20%! That's horrible!
T/F 5-6 million people need HAs
true
T/F INPUT + VOLUME (gain) = TOTAL OUTPUT AMOUNT
true
T/F the HA microphone converts sound waves to electrical signals
true
True or false: hearing aid rehabilitation is the equivalent to a conductive hearing loss, therefore hearing aids do not restore hearing to normal
true
True or false: most hearing aids have different gain levels for soft, moderate and loud incoming sounds
true
True or false: only 20% of individuals who need hearing aids actually wear hearing aids
true
True or false: when amplifying sound, you still need to maintain dynamic range. For example making whispers still sounds like whispers.
true
__ - ___ million people need HAs
5-6
We know that HA GAIN is how much has been added to the input (dB). If you have Input level: 30 dB SPL, and Output level: 80 dB SPL. What is the GAIN?
50 dB because the input (30, whats in the environment) and you have 80, so 80-30=50 dB SPL
What is the difference between the In the Ear (ITE) and in the Canal (ITC) style HA?
In the ear: Fit in the whole concha In the canal: Fit small portion of concha BOTH No external tubes or wires
On average how long does a hearing aid battery last for?
Last for 3-4 days to 3-4 weeks depend on the size of the battery and the duration of everyday usage.
What exactly do hearing aids do and which of the three is the most important?
Makes speech audible *MOST IMPORTANT Optimizes intelligibility Assures optimal dynamic range
We know the average cost of a single hearing aid digital is between 1000 and $3000. How much do you insurance companies cover on average?
Many insurance companies do not provide coverage for HAs
There are two ways to control the Level of HA Output. One, PEAK CLIPPING, and two, COMPRESSION. Explain method 1
Method one: Peak clipping (the addition of non original) Cut all above a certain level Adds distortion Sounds unnatural
There are two ways to control the Level of HA Output. One, PEAK CLIPPING, and two, COMPRESSION. Explain them both
Method one: Peak clipping Cut all above a certain level Adds distortion Sounds unnatural Method two: Compression Compresses the peak Reduces distortion Comfortable, less harsh Is electrically treated, not acoustically The cut-off level is determined based on the patient's uncomfortable level
There are two ways to control the Level of HA Output. One, PEAK CLIPPING, and two, COMPRESSION. Explain method 2
Method two: Compression (things get loud as the hearing aid decides) Compresses the peak Reduces distortion Comfortable, less harsh Is electrically treated, not acoustically The cut-off level is determined based on the patient's uncomfortable level *The graph shows that Rather than at getting a loud, output goes at a slower rate
What is the hearing aid microphone susceptible to?
Moisture, water Vibrations Wind noise Internal electrical noise
What are some advantages to the behind the ear hearing aid?
Advantages: Most powerful Wide frequency response Less feedback noise Easy to handle More options
Modifying the Earmold and/or Tubing
Affects the property of acoustic signals Venting: affecting low frequencies Damping: affecting mid-frequencies Horn tubing: affecting high frequencies
What kind of hearing aid style is the best option for children?
BTE!! BEHIND THE EAR! Change only the earmold as the child grows. Safer when using a soft earmold Most have a FM system option which is important for the school setting
Why is the battery such an important basic component of the hearing aid?
Because it powers the microphone, amplifier, and speaker/receiver
What style hearing aid is more prone to wind noise?
Behind the ear
What are some reasons the behind the ear hearing aid style is the best for children?
Change only the earmold as the child grows. Safer when using a soft earmold Most have a FM system option which is important for the school setting
How long will a battery last?
Depends on the size of the battery. The larger the battery , the larger the hearing aid but large batteries do you tend to last longer
What is the cost of a single hearing aid range from?
Digital: $1000 - $3000
What are some benefits to the OPEN-FIT BTE?
Eliminates the occlusion effect Cosmetic appeal Suitable for patients with mild to moderate high frequency loss
T/F Hearing aids are a great option to restore hearing to normal
FALSE FALSE FALSE!! Hearing aids do NOT restore hearing to normal!
True or false: the open fit BTE is best for low frequency hearing loss
False! It is not good for low-frequency loss. It is most of the ball for patients with mild to moderate high frequency loss
True or false: on average, you can get about 10 years out of a hearing aid
False! You can get about five years
What is the EYEGLASS styled HA?
Generally no longer in use
I know there are phone options for hearing aids. Explain Bluetooth wireless
Hearing aids are paired to their call phone directly or with the use of a remote
The Electroacoustic Properties of Hearing Aids include gain, output, max power output (mpo), distortion, and equivalent noise. Explain GAIN
How much has been added to the input (dB)
