Hearing Aids

Infants need the signal to noise ratio to be _____ more than adults for discrimination of syllables

+26 dB

Children need how much more of a signal-to-noise-ratio than adults to function in noise?

+3dB - +7dB

Optional Hearing Aid Features

-Volume control -Programs -Telecoil -Direct Audio Input & or Bluetooth' Frequency compression Remote control

In the Ear (ITE) hearing aid fit

-aka full shell -fill the supper regions of the ear and sometimes even the helix of the ear

In-the-canal (ITC) hearing aid fit

-aka half shell - hearing device fills the bowl in the ear

Invisible-in-canal (IIC) hearing aid fit

-completely invisible -deepest fitting hearing device you will find

earmold

-device that is essentially a custom fit tube which takes sound from the hearing aid into the ear -BTE Tubing can be a problem (size) May need to make modifications for fit Venting is difficult if at all possible due to size The sound bore can be too narrow due to size of ear canal (less than 2mm can cause detrimental effects to the high frequencies in the speech range) Always made of soft material

Reciever in the canal (RIC) hearing aid fit

-hearing device sits behind the ear and a small wire is located in the ear canal that is attached to the reciever -wire is coupled with a dome

Completely In the Canal (CIC) hearing aid fit

-little bit larger than the IIC (invisible in the canal HA) -sticks out slightly -oftentimes cannot be seen straight-on

Behind the Ear (BTE) hearing aid fit

-portion of the hearing aid sits behind the ear -attached to an ear mold that goes into the ear and sometimes fill the while bowl of the ear up to the concha

hearing aid analyzer

-probe microphone is usually connected to this device for speech mapping -measures frequency response and OSPL 90 of hearing aid to ensure it is functioning properly -compared against ANSI standards

Real ear measurements are critical because

-the volume differences will affect the SPL arriving at the eardrum, affecting critical info needed to fit and program the hearing aid properly -children cant tell us if its too loud or uncomfortable

microphone

-where the sound is picked up -the sound is converted from an acoustic signal to an electrical signal

What are the goals for fitting a child with hearing aids or any other listening device?

1. To make speech audible without introducing distortion or discomfort 2. To restore a range of loudness experience (compression) 3.Maximize the use of residual hearing for speech and language development

What are the 4 basic hearing aid components?

1. microphone 2. amplifier 3. reciever 4. battery

Difficult to fit ITE (in the ear) in a small ear bc?

Small ears grow rapidly and would have to re-case ITE often (not cost effective)

Analog

This was the tech in hearing aids until about the year 2000. settings and sounds are both processed via analog technology. No longer available except used as hearing aid or from online retailers

T/F hearing aid microphone can be manual or auto

True, Different Modes/programs can be manual or auto selection

compression is often called?

Wide Dynamic Range Compression

loudness summation

a summing of the signals received by each ear, resulting in a 6dB advantage for binaural over monaural hearing -the volume doesn't have to be as loud compared to using just one device

Frequency compression

aka frequency lowering -shifts or compresses the high frequency sounds to a lower frequency range where hearing is better

probe-microphone or real ear system

aka speech mapping -measuring what is coming out of the hearing aid by putting a small microphone near the eardrum

Direct audio input/ bluetooth

allows hearing aid to receive transmitted signal instead of or in addition to the acoustic signal ex: cell phone, TV, ipod, personal assistive listening device in classrooms

programs

allows the audiologist to set programs for different listening environments ex: car, theater, music, tv, restaurant

Volume control

allows the patient to vary the gain within a set bracket programmed by the aduiologist

remote control

allows user to change programs or volume with a handheld device -some are connected to phone

speech enhancement/noise reduction

an algorithm to detect patterns of speech and attempt to amplify them over other patterns (noise)

BTE

behind the ear

binaural fittings result in a slight increase in signal to noise ration due to the "________ _________" effect

binaural squelch

Digital

both settings and sound are processed digitally. Hearing aids are programmed and adjusted via programming software. Levels of digital tech are based on the number of channels noise reduction sophistication, and extra features.

what is peak clipping?

clips off sounds once they reach a certain level to maintain comfort

what is compression used in?

compression is used in modern digital hearing aids

receiver

converts the signal back to an acoustic one and transfers the sound to the ear

Why is peak clipping bad?

cut off speech that is too loud and would decrease intelligibility -used in linear hearing aids

acoustic feedback cancellation

designed to help eliminate "whistling" or feedback from the hearing aid

In noisy/social situations what microphone direction might you chose?

directional can be more beneficial to help decrease background noise and focus on the speaker in front of the user

"Half gain rule" appears to apply to children in terms of preference but not in terms of need. To learn, children need more ______________ than adults.

ex: 40dB of hearing loss set the gain for 20dB

front facing microphone

focuses on one direction

A person who cannot hear high frequency sounds would benefit from?

frequency compression, or shifting the high frequency sounds they cannot hear to a lower frequency

The volume control on the hearing aid is changing the?

gain

what is compression?

gives non-linear volume adjustment to incoming sounds to maintain comfort and audibility

Binaural Squelch Effect

if noise and signal are presented to both ears at the same time, the brain can effectively cancel out the noise

telecoil

induction coil that receives magnetic signals/energy ex: landline telephone receiver or loop amplification system in rooms

How do bone conduction hearing aids work?

info is picked up by microphone and passed through bone conduction

Children most likely need more gain for __________ _______sounds than adults but NOT for _________ ________ _________

intensity sounds higher intensity sounds

linear gain is applied until a certain level called the _____ point and then compression is applied

knee point

binaural fittings can take advantage of _________ _______

loudness sumation

What are the basic hearing aid components?

microphone program button volume control battery compartment tone hook (connect to the ear mold) ear mold

in compression, you give _____ amplification to less intense sounds and _________ amplification to more intense sounds

more less

BTE or behind the ear is the most popular option style for?

more popular style for kids

RIC recieve in the canal is the most popular style for?

most popular style in the US

In quiet situations which microphone direction might you chose?

omnidirectional may be more beneficial because you can hear noise all around you

Reciever in the canal are also known as?

open ear BTE or receiver in the ear

Rear omnidirectional microphone

picks up sounds from all directions

battery

powers the hearing aid

target gain is based on

pre-set algorithms and hearing loss

amplifier

processes the signal and increases the intensity

If a patient would like a special setting in the HA for eating at a restaurant with friends, the audiologist can set a ______?

program

RIC

receiver in the canal

In kids, the volume between the ear mold and the eardrum will be _____________.

smaller

What is gain?

the amount the amplifier increases the incoming signal aka volume

binaural fittings eliminate what effect?

the head shadow effect and may aid in localizing sound

head shadow effect

the loss of intensity of a sound as the sound travels around the head

What is maximum power output?

the maximum output of the hearing aid at each frequency (aka what the amplifier is capable of doing at a particular frequency)

bone anchored hearing aid (BAHA)

transmits the signal to the cochlea via bone conduction -have to be at least 5 years old to have the surgery -more invasive

T/F Multi-band compression allows for different knee points and different compression ratios across different frequency bands

true

T/F two hearing aids are better than one

true generally binaural hearing aids are better than just one

reasons why someone would pick monaural vs binaural HA?

two aids are more expensive and more maintence

Where are body aid hearing aids used?

used in the developing world

Hearing aid orientation

1.Describe the function of each part of the hearing aid 2. Discuss how to care for and clean the hearing aid 3. Practice insertion and removal of the aid and batteries 4. Describe why this device was chosen, and realistic expectations for the patient, and the limitations of the hearing aid 5. Discuss acclimatization and wearing schedule (Analogy of the train) sometimes set volume lower to acclimate the person 6. How to troubleshoot the hearing aid 7. Details of the warranty most warranty 2-3 years

What batteries are the most common?

10, 312, and 13

which battery is the largest?

675

the ear canal resonance for infants is closer to __kHz instead of ____kHs as in kids or adulrs

6kHz 2.5KHz

IIC

Invisible In the Canal

What are benefits of BTE for children?

BTE is better able to attach devices for retention So child does not remove and put in mouth, throw, etc. Require less maintenance

Style of hearing aid is generally a __________ for children until adolescence

Behind-the-Ear (BTE)

ITC

In The Canal

CIC

Completely In the Canal

ITE

In the Ear

T/F peak clipping used in modern hearing aids?

False, peak clipping was used in linear hearing aids