Aural Rehab #2

T or F Classrooms are typically noisy environments. Studies have consistently shown that SNRS in classrooms are poor. On the order of ____ to ____ dB

+5 ... 0 dB

The signal to noise ratio is sometimes referred to as..

Message to Competition Ratio (MCR)

This is a transducer which picks up sound from the environment and changes it to an electrical form of energy. It changes the incoming signal in dBSPL pressure to an electrical form (voltage)

Microphone

The ______ is worn by the teacher. Most use a clip on lapel or head worn boom attached via a cord (the antenna) to the transmitter

Microphones/Transmitting unit

An audible acoustic energy that adversely affects the physiological or psychological well-being of people.

Noise

What are the most common causes of auditory distortion?

Noise Reverberation Distance

What are some hearing aids with connectivity or bluetooth.

Oticon streamer Phonak icom Widex M-Dex

Federally mandated that all corded and cordless phones sold in this country be compatible with hearing aids. On pay phones those with blue grommets are compatible with hearing aids.

PL 97-410 Telecommunications for Disabled Act

Comprehensive study of noise levels in everyday environments. Completed for EPA

Pearsons, Bennett & Fidell

The percentage of individuals who have/use haring aids out of all who could benefit from aids.

Penetration Rate/Adoption rate

Who can noise cause a breakdown in?

Persons with normal hearing and hearing loss. Typically noise affects persons with hearing loss to a greater extent than those with normal hearing.

These units are worn by the student. Most have volume controls. Some have a setting (program) which allows the student to receive the FM signal from the teacher, and at the same time monitor their immediate acoustic environment.

Receivers

Listener seated in enclosure...

Receives sound directly from a source along with reflections delayed in time

A phenomenon by which direct acoustic waves bounce off reflective surfaces back into the acoustic space.

Reverberation

Causes time delays in the signal reaching the ear This causes overlap with the direct signal Time-Masking Effect

Reverberation

The time is takes for reflected sounds to die down by 60 decibels from the cessation of the original sound signal. (measured in secs.

Reverberation

Phonaks series of wireless communication devices ______

Roger

Other receivers...

Roger Receiver ML14i - Receivers for Cochlear implants

Late arriving reflections tend to ____ the direct sound signal.

SMEAR

What are some Phonak transmitters....

Smartlink SX- phonak Easylink S-Phonak Inspiro from phonak Widex Versatile Mic/Transmitter Multi-Channel capacity Capability for team teaching function Allows user to listen 2 FM transmitters Simultaneously FM microphone for personal and educational use Multi-Channel capacity Alkaline or rechargeable batteries

Why is an ear impression necessary?

So the exact geometry of the patients ear can be replicated to ensure a proper fit. Custom device different styles and colors

Need to limit the output of the amplifier so it never exceeds a comfortable level for the patient. We do this by..

Some form of compression

T or F Children with hearing loss struggle in environments filled with noise, reverberation, and distance from the speaker. It is known that school-age children encounter these poor listening conditions everyday in the classroom.

T

T or F Even kids with normal hearing can benefit from those amplification systems

T

T or F Fitting of hearing aids is complicated and detailed.

T

T or F Good to provide orientation with significant others present. SO can help with better understanding of how they work, and may increase acceptance of HA with patient.

T

T or F New legislation has been adopted for compatibility with cell phones Benchmarks were set in 2003 and 2008.

T

T or F Personal hearing aids alone are not sufficient for deaf and hard of hearing children to use in the classroom

T

T or F Rarely do we listen in environments with only one source of distortion.

T

The important thing is that both the transmitter and receiver are tuned to the same frequency. T or F

T

One of the most detrimental sources of noise is...

The children themselves

What is the Head shadow effect?

The head creates a "shadow" between the two ears. This affects the transmission of high frequency sounds from one side to the other.

What is the goal in fitting hearing aids?

To amplify as much of the speech spectrum as possible and keep the auditory signals within a comfort range for the patient.

What are some battery reminders?

Turn off when not in use Open battery door when aid is not in use Remove tab on zinc air before inserting and let battery set for 2 minutes before inserting Keep battery contacts clean Be sure battery is inserted correctly

What is the lombard effect?

We tend to raise the intensity level of our voices during communication as the level of background noise increases. What we try to do is increase the SNR by attempting to make speech louder than the background noise

Batteries used today in hearing aids are ______ type. With a voltage of ____

Zinc air 1.4-1.45 volts

It is rare to be in communication situations without the presence of some type of _____

auditory distortion

What are some advantages of binaural hearing aids?

better localization elimination of head-shadow effect better hearing in noise loudness summation wider dynamic range due to summation more balanced feeling reduces concern for auditory deprivation

Noise can cause _____ in speech perception

breakdown

In operation the teachers voice is ______ from a ______ on a radio frequency to a _____ worn by the student which is set like a radio or TV to the same ___ as the transmitting device from the teacher.

broadcast transmitting device receiving unit channel

Reflected sound tends to _____ to a level louder than direct sound. Reflected sounds ___ direct sounds.

build up mask

When both speech and noise are reverberated...

causes a greater smearing of the speech signal.

Some of the newer hearing aids have remote controls which can be used to ______

change function (from mic to telecoil) change listening program Change volume

The majority of receivers are small units which are attached to the ______ These type of receivers can only be used in conjunction with BTE style instruments.

child's personal hearing aid

Widex=

connects to the TV takes out the remote and u can stream TV directly into hearing aids.

The distance at which people communicate _____ as the background noise ______ (we try to improve SNR)

decreases ; increases

Issue with directional microphones

does not help with distance provide little benefit with reverberation

Lyric-disposable hearing aids are inserted deep in the ______ near the ____

ear canal. Tympanic membrane 16mm

Children with normal hearing and children who are deaf and hard of hearing need more ______ than adults especially in the ____

favorable SNRS Classroom

Assistive listening device ...

improves SNR and decreases negative effects of distance, reverb, and noise dependent on type of device and acoustic environment

What are some other sources of noise....

inside the classroom outside the classroom inside the building outside the building

Reflections that are delayed long enough.....

interfere with direct signal and affect speech perception

In larger cities there have been complaints that some of the newer radio technologies such as pagers and cellular phones are _________

interfering with FM systems

While telling the patient how the hearing aid works you should use____

lay terms and visuals -show them the parts and controls of the hearing aid.

Transmisson range may be affected by....

metal barriers, condition of the batteries in the FM and hearing aid, and local interference and radio transmission

Most often we listen in the presence of ___ and ___

noise and reverberation

Digital Noise reduction...

provides some comfort in noise

What are some interference sources outside....

radios cell phones fax machines pagers

Impact of listening in noise

reduces incidental learning Theory of mind---> social interaction increases fatigue reduces rentenion

Classroom Ts is variable depending on ____ and _____

room size; reflective surfaces

Reverberation times are recorded in ...

seconds or fractions of a second

Reverberation induced reduction in speech recognition occur at _____ times than for normal hearing listeners *especially for children*

shorter

The concern is that the children's abilities to listen in noise may affect a variety of areas like...

speech and language, educational performance, social/emotional development.

Within these bands there are a series of narrow band channels. Each company uses their own ______ the frequency on which the system is transmitting.

system to code

How long can you wear lyric disposable hearing aids.

up to 3mo device is removed then a new one inserted

When is reverberation good?

when listening to music reverberation adds to the liveliness of the sound

For transportation vehicles the SNR is often ____ or poorer

0dB

What are the 3 important factors for selecting a hearing aid for an adult?

1. Degree of hearing loss 2. motivation to use aid 3.Communication difficulties

Reverberation time should not exceed _____ for ideal acoustics

6s

Behind the Ear (BTE) accounts for about _____ of sales

70%+

The BTE-FM My Focus are for children who ......

APD, Autism Spectrum Disorders, Unilateral Hearing loss

It is hard to listen in noise you can see the person clearly, but you can't pick out what they are saying. ____ have an especially hard time doing this, esp ____ with hearing loss.

Children

Describe delay time...

Dependent on the reflective characteristics of the room Rooms with more reflective surfaces have longer reverberation times The longer the reverberation time the more detrimental to speech recognition

Why is the loss of acoustic cues less devastating for adults than children?

Differences in cognitive-linguistic background Affects of redundant cues Better able to fill in missing parts

This type of microphone has two inlets for sound; one on the front of the aid and another on the back. They are differentially sensitive to sound location. They act to reduce sounds from behind the listener, thus improving the signal to noise ratio.

Directional Microphones

_____ is required for all hearing aid styles except some open ear fittings.

Ear impressions

When using BTE (behind the ear) or body style hearing aids you need a device to couple the hearing aid to the patients ear. ____ are designed to do this.

Earmolds

Microphone picks up sound from the environment and changes it to an _____ form of energy. Changes from _____ to _____

Electrical pressure (dBSPL) voltage (electrical)

Receivers transduction process.....

Electrical to Acoustical energy

What are some examples of Noise?

Environmental Sounds (trucks, cars, washing machines) Speech or Music

After fitting the hearing aid what do you do?

Go over the use and care of the hearing aid. The composition and intensity of the orientation will depend on the needs of the individual. Post fitting procedures Hearing aid orientation

How can the GAIN be regulated?

Having the patient change the volume control, or in many digital hearing aids, the gain is automatically reduced if the input or output level to the hearing aid exceeds a certain value.

Variation of ITE only smaller. Partially in the concha Leaves a portion for natural resonances of outer ear Used for mild-moderate losses.

In the Canal (ITC)

BTE plug in receiver..

MLxi

What are the 4 basic Components of hear aids?

Microphone Amplifier Receiver Battery

Typically ____ classrooms have lower Ts

Newer

GAIN =

Output - Input

Operate like loudspeakers

Receiver

_____ characteristics of noise and speech are similar resulting in a greater ____ effect

Spectral Masking

What are some things that need to be consider for picking a hearing aid?

Style and type of aid earmold type Monaural or binaural fitting Extra features frequency/gain characteristics cost to the patient

The telecoil is typically engaged by the use of a _______ located on the hearing aid. Some are automatically switched on when the phone is close enough to the hearing aid. Telecoils are not available in some of the smaller hearing aids due to space limitations.

Switch/button

Overall effect is greater than predicted by simply adding the decreases for noise and reverberation alone.

Synergistic effect of noise and reverberation

T of F There are some manufacturers that have aids with rechargeable batteries.

T

T or F ANSI standards on classroom acoustics are not mandatory

T

T or F Any child with a significant hearing loss, including sensorineural, conductive, or mixed loss of any degree should be considered a candidate for amplification. Fittings should be completed as soon as possible after identifying the hearing loss.

T

T or F Not all reverberation is bad

T

T or F Research has shown that even children with normal hearing struggle with speech in noise tasks.

T

Originally designed to help HOH persons use the telephone more effectively. Its purpose has been expanded beyond this to include use with various assistive listening devices like FM units.

Telecoil

Small coil made up of numerous windings of copper wire around a metal bar. _______ from the telephone receiver is picked up by the telecoil and amplified by the hearing aid. Thus, the telecoil becomes the input to the hearing aid

Telecoil Electromagnetic Energy

What are some other features of hearing aids?

Telecoil Output limiting Listening programs Remote control Directional Microphones Volume control

Define Signal to Noise Ratio

The ratio of the speech signal (intended signal) to that of the background noise

The receiver like the microphone is a ____ and the process here is the ____ compared to the microphone.

Transducer Reverse

What are some interference sources inside.....

computer screens walls/metal lights wiring internet cable sys

What are some advantages of FM systems

consonant favorable SNR Mobility between speaker/listener Compatibility with personal hearing aids and other assistive devices Portability Can be packaged in a BTE unit

The Signal to Noise Ratio is expressed as a ______

decibel value

It _________ between channels to avoid interference issues and only uses free channels.

frequency hops

Researchers made noise measurements in numerous daily settings like.....

hospitals classrooms homes shopping areas transportation vehicles.

What are some things you should show the patient?

location of microphone any special switches battery compartment and how to insert the battery(write down battery size) how to operate the volume control how to insert the aid and take it off how to clean the HA (BTE how to clean the mold) use of remote control or bluetooth device troubleshooting

The ____ the reverberation time the more detrimental to speech recognition.

longer

SPiN stands for

speech perception in noise

Overall the long term consequences of OME remain ____

unclear

ICom TV package =

wireless connection to TV

Research has demonstrated that FM systems provide an improvement in SNR of ____ to ____ over conventional hearing aid.

+10 to +15 db

The SNR at the student's ear should exceed a minimum of _________ ideal acoustics

+15 dB

Children who are hard of hearing need SNRs no less than __________ this is particularly important for schools which use inclusion models.

+15 dB to +20 dB

FM systems are capable of providing a SNR of ____ to ____ dB provided they are used appropriately.

+15 to _+20

S= 60 dB N=55 dB SNR=

+5

In public areas the SNR typically varied between ____ and ____ dB

+5 - +8dB

Normal hearing children require a SNR of at least ______ for optimum communication efficiency

+6dB

Most typical SNR for adults was _____

+8dB

s= 60 dB n=65 dB SNR=

-5

For normal hearing children listening in either noise and reverberation adult like speech recognition performance is not reached until about _____ years of age.

13

Runs on a _____ G Hz band

2.4 GHz band (for wifi) Roger

Audio signals are digitized and packaged in very short digital bursts of codes and broadcast several times at different channels between _____ and ____

2.40 - 2.485

Many of the FM systems that are used in educational systems operate on radio frequency from __________ also called ______

216-217 (N band)

In 2015 there were over ____ hearing aids sold in the US.

3 million

Sound treated rooms have Ts of about ___

3 secs

Transmitting range for FM systems can be up to _____

30 m

In a poor, but commonly reported classroom environment (SNR=0 RT= 1.2s) perception scores were reduced to less than _____

30%

The Penetration/adoption rate is currently ____

30.2%

ANSI-Unoccupied noise levels should not exceed______ especially for new or remodeled schools.

35 dB

Noise which is typically _______ dB is often the same as

60dB loudness of teachers voice

A penetration rate of nearly 25% means that roughly _______ of those who could use a hearing aid don't have one.

75%

Crukley et. 2011 reported elementary and high school students spend almost ____ of their day in noisy listening environments

75%

What are some ways to meet acceptable standards?

Acoustical modification of classroom Reduce speaker-listener distance Use classroom amplification systems

What are FM systems?

Amplification systems that are typically used in classrooms to improve the SNR for students, due to poor classroom acoustics. They can be used by themselves or dovetailed to a personal hearing aid.

Increases the electrical voltage from the microphone--it makes it larger. GAIN is important here.

Amplifier

What is our model of speech perception?

Auditory & Visual Factors can affect speech perception

A decrease in speech recognition in an ear over time due to lack of auditory stimulation.

Auditory deprivation

Electronics are housed in a curved plastic case which fits behind the ear Can fit a wide range of HL The amplified signal from the aid is fed to the ear via tubing and ear mold.

BTE Behind the Ear

Power source for the hearing aid.

Battery

When we listen with 2 ears the sounds from the ears "add" in the central auditory systems and increase loudness perception.

Binaural summation

Used with persons who have conductive hearing losses when an air conduction aid cannot be used. Ear drainage Atresia(no opening to ear) Surgical issues.

Bone conduction hearing aids.

Smallest style of aid available. Aid fits completely in the ear canal High cosmetic appeal limited use of volume control, directional mics. Removed with transparent wire.

Completely in the Canal (CIC)

Squeeze the amplified signal into the audible and comfort ranges of the patient. These circuits typically act to reduce the gain of the hearing aid as the output or input of the hearing aid increases. WE can even do this independently for low and high frequencies.

Compression

What are some things that affect the life of a battery?

Daily usage Volume control setting Heat/Humidity Circuit requirements Battery size

FM systems operate on the same principle as an ____

FM radio

These bands have been set aside for assistive listening devices (ALDS) for the hearing impaired by the _____

Federal Communications Commission FCC

FM Systems stands for...

Frequency Modulated Systems

The most frequently used sensory aid for persons who are hard of hearing and deaf. (sensorineural hearing loss )

Hearing Aids

What is signal to babble ratio?

Here the noise is specific-speech babble (noise composed of many speakers talking at once)

Normal hearing children require _____ SNRS and _____ RTS (reverberation times) than adult normal hearers to achieve equivalent perception scores.

Higher; Lower

The hearing aid fits directly into the external ear. The circuitry is housed in the concha area The largest of all the ITE styles therefore can be used with more severe losses and use more sophisticated circuitry

ITE (Full or half-shell)

The entire hearing aid, including the electronic components, fit into the patients ear. These styles make up under ____ of the market sales.

In the Ear (ITE) 1/2

Negative values

Indicate that the noise is present at a greater intensity than the signal

Positive values

Indicate that the speech is present at a greater intensity than the noise

How is consonant favorable SNR achieved?

It is achieved because the input to the system microphone is placed close to the speaker (teacher or students mouths) hearing aids the input is located at a distance far removed from the speaker

What are some advantages of Zinc Air Batteries?

Last longer Longer shelf life Less Expensive Contain no chemicals that may affect the environment

Consequences of loss of acoustic cues?

Less devastating for adults than children

Some of the moderately and higher priced hearing aids have stored programs (algorithms) that affect how the hearing aid operates in various listening situations. They are used to optimize audibility and comprehension in specialized situations. Like the telephone or listening to music.

Listening programs

How can you minimize noise and reverberation?

Locate classrooms away from external noise sources Use landscpaing Located away from areas like gym, cafeteria Use internal acoustical treatments Minimize speaker-listener distance Use small group instruction Consider amplification systems such as free field or FM systems

These individuals have a reduced range between when sounds are audible and uncomfortably loud. For them, loudness perception grows abnormally fast.

Loudness Recruitment Persons with sensorineural hearing losses

In higher noise environments, the average distance =

.4 meter

Many adult environments have Ts of _____ to _____

.5 - .75 secs

Classroom Ts may vary from....

.6 to 1.2 secs

In the home the average distance for conversation =

1 meter

Why do you need an FM system?

1. All people with sensorineural hearing loss exhibit greater difficulty understanding speech in background noise 2. The world is a noisy and reverberant environment 3. All kids have greater trouble understanding speech compared to adults 4. Therefore kids with hearing loss need an FM system

What are the four major styles of hearing aids?

1. Behind the Ear (BTE) 2. In the Ear (ITE) 3. In the Canal (ITC) 4. Completely in the canal (CIC)

What are the three functions of the earmold?

1. Couple the hearing aid to the patients ear 2. Provides support for the BTE aid 3. Directs and modifies the amplified sound that reaches the ear canal.