Lecture 9

Question 1

Aural rehab model

Answer 1

Sensory management
Instruction
Perceptual training
Counselling

Question 2

Hearing assistance technology

Answer 2

To overcome the difficulties of hearing in adverse listening conditions
To alert individuals to important environmental sounds

Question 3

Background room noise

Answer 3

Masks the weaker transient consonant phonemes more than vowels and 80-90% of acoustic info important for speech perception comes from the consonants

Question 4

Signal to noise ratio

Answer 4

Level of speech signal relative to level of noise, measured in decibels
Classroom environments can range from 5 to -7 but kids with sensorineural hearing loss need 4 to 18 dB to achieve same speech perception as kids with normal hearing

Question 5

Critical SNR

Answer 5

Ratio at which 50% of speech is understood
For normal: -6 dB
For severe to profound loss: 15 to 20 dB
A loss of even 1 dB in critical SNR could reduce a speech score by as much as 20%

Question 6

Reverberation

Answer 6

Prolongation or persistence of sound within an enclosure when sound waves bounce off hard surfaces
Results in masking consonants
Measures in classrooms: 0.4-1.2 seconds
With hearing loss: needs 0.4-0.5 seconds

Question 7

Acoustic room modifications

Answer 7

SNRs should be about 15 dB
Unoccupied noise levels should not exceed 30 to 35 dB
RTs should not surpass 0.4 seconds
- acoustic ceiling tiles, carpeting, draperies, glides on chairs, elevated projector tables, smaller desks

Question 8

Telecoil

Answer 8

Metal rod that is encircled by many turns of a copper wire
Detects the electromagnetic field from phones or induction loops
Converts magnetic energy to electrical energy and in turn, hearing aid converts to speech signal, heard by the listener

Question 9

Electromagnetic loop systems

Answer 9

Alternative use for the telecoil
Most often used in churches or small theatres
Loop is laid on the floor and people sit within the loop
Can use telecoil or a loop receiver

Question 10

Infrared systems

Answer 10

Electromagnetic radiation with a wavelength longer than that of visible light
Coupling with headphones, receiver with neckloop, or telecoil
Used for television, large theatres or auditoriums, confidential settings, works best when no bright sunlight

Question 11

Frequency modulation (FM)

Answer 11

Microphone > detects speech signal and converts to FM signal
Receiver > receives the incoming FM signal and is attached to hearing aid or headset
Coupling > transmits FM signal from transmitter to receiver
Educational or vocational environments
Churches, auditoriums, theatres

Question 12

Direct audio input (DAI)

Answer 12

Previous systems used wires

Most utilize an audio shoe/boot that connects to receiver or is integrated with receiver

Question 13

MyLink

Answer 13

FM system receiver for ITE hearing aids
Receives signal from a transmitter
Relays signal to hearing aid via telecoil

Question 14

Frequency synchronization

Answer 14

Can synchronize to a channel being used in that room, so students and teachers are all on the same channel

Question 15

Bluetooth

Answer 15

Short range wireless communication between electronic devices without the need for the FM system
“Pair” the hearing aids connection device to the phone, tv or music player

Question 16

Visual signallers

Answer 16

Hook up to lamps, overhead lights, etc
Doorbells
Telephone ring
Smoke detector
Alarm clock

Question 17

Auditory signalers

Answer 17

Louder doorbells
Lower frequencies
Amplified telephone ringers
Hearing service dogs

Question 18

Tactile signalers

Answer 18

Pagers
Vibrating wrist watches, cell phones, alarm clocks
Universal alerting system

Question 19

Personal amplifier

Answer 19

Simple microphone and headset amplifier
For those who cannot handle a hearing aid
Good in a hospital or care facility