Assistive Listening Devices

Question 0

Goals of assisting listening devices

Answer 0

Improve SNR
Electronically reduce the distance between talker and listener
Assist in face to face communication
Assist in enjoyment of broadcast/media
Assist in telephone communication
Assist in awareness and identification of environmental sounds

Question 1

Signal to noise ratio

Answer 1

Level of sound signal relative to background noise

Question 2

Factors that affect a listeners access to auditory information

Answer 2

Level of sound source
Distance between source and receiver
Level of background noise
Room reverberation

Question 3

4 categories of assisting listening systems

Answer 3

Personal/group amplification devices
Television amplification devices
Telephone devices
Signaling devices

Question 4

Induction loop systems

Answer 4

Wireless - uses telecoil on hearing aid 
Components:
Loops around room
Mic placed near sound source
Receiver-amplifier

Question 5

Infrared systems

Answer 5

Wireless - transmission by infrared light beam
Components:
Mic to pick up sound from source
Infrared converter to change electrical energy to light energy
Receiver/headset

Question 6

FM systems

Answer 6

Wireless, transmission by FM radio waves
Components:
Mic transmitter placed at sound source
Receiver worn by listener

Question 7

Telephone amplification devices

Answer 7

Telecoil not always efficient with phone
Telephone amplifiers increase loudness of phone signal 
Examples: 
- handset amplifiers 
- portable amplifiers 
- acoustic telepads/couplers

Question 8

Visual devices

Answer 8

Closed captioning
Real time captioning
Projection note taking techniques
Computer assisted note taking

Question 9

Alerting devices

Answer 9

Electronic:
- visual
- auditory
- kinesthetic
- air stream
Mammalian:
- hearing dog

Question 10

Uses for alerting devices

Answer 10

Telephone ring
Doorbell
Smoke detector
Wake up alarm
Baby cry