Amplification - Special Features

Question 1

What are 5 special features that can be used in HAs?

Answer 1

1) telecoils
2) directional microphones
3) direct audio input
4) special amplifiers
5) noise reduction circuitry

Question 2

What are telecoils?

Answer 2

A small induction coil which changes electromagnetic energy into electrical energy

Question 3

How are telecoils use?

Answer 3

Telephone receivers emit an electromagnetic signal and the telecoil in the HA can pick up the signal, essentially replacing the mic

Question 4

Why is using a telecoil for phone calls better than just holding the phone up and using the HA mic? (2)

Answer 4

• the HA mic with a phone can cause feedback

- it only amplifies the phone call signal, not any background noise

Question 5

When telecoils were first used in HAs, it was _____, then phone design improved but the _______ wasn’t as strong. So since _____, the FCC has required what?

Answer 5

Good
Signal
1989
That all phones sold in the US be HA compatible

Question 6

The FCC requirement for phone HA compatibility didnt include what which led to what issue? But why is this not really a problem?

Answer 6

Cell phones, so not all cells are compatible

But most HA user benefit from /use Bluetooth more

Question 7

How does an HA user activate the telecoil? (2 ways)

Answer 7

With a switch with the options M, T, or MT (and there are also automatic telecoils that sense electromagnetic fields and automatically activates)

Question 8

What are the 3 options on an HA for telecoil settings?

Answer 8

M: mic
T: telecoil
MT: both

Question 9

Originally telecoils were designed for what but now they are widely used for what?

Answer 9

Phone

Couple HAs with assistive listening devices

Question 10

If a person has/uses an ALD they should purchase an HA that has what?

Answer 10

Strong and reliable telecoils

Question 11

What is one special feature of HAs that you almost always want?

Answer 11

Directional microphones

Question 12

What are the 3 possibilities for HA mics?

Answer 12

1) directional
2) omnidirectional
3) both

Question 13

What are directional microphones?

Answer 13

More sensitive to sounds coming from a particular direction

Question 14

What are omnidirectional microphones?

Answer 14

Approximately equally sensitive to sounds coming from all sides

Question 15

What types of HAs are directional mics available for?

Answer 15

BTEs and ITEs (larger)

Question 16

What is the benefit of directional mics?

Answer 16

significantly enhance SNR, and therefore improve speech understanding

Question 17

Where do directional mics lose some of their effectiveness?

Answer 17

Reverberant environments

Question 18

How are directional microphones turned on and off?

Answer 18

• manual option
• automatic switch based on listening environment
• most advanced “focus” the mic based on where speech is occurring

Question 19

What is Direct Audio Input?

Answer 19

Means of delivering an electrical signal directly to an HA by means of a snap-on “boot” or “shoe” that established an electrical connection to the HA

Question 20

DAI is typically only available in _____, and is widely used for what?

Answer 20

BTEs

Couple assistive listening devices to an HA

Question 21

Which 3 types of HAs require a seperate piece, and what is is?

Answer 21

1) BTE
2) body
3) eyeglass
Earmold

Question 22

What is the function of an earmold?

Answer 22

Direct amplified sound toward the TM in a way that prevents feedback

Question 23

The selection of earmold styles is based on what 3 things?

Answer 23

1) feedback prevention properties
2) client comfort
3) cosmetic preferences

Question 24

Why do we (almost) always use earmolds with children?

Answer 24

More secure and durable

And there are fun styles!

Question 25

What are possibilities for earmold materials?

Answer 25

• hard acrylics to softer/pliable

- hypoallergenic

Question 26

What material is typically used for children’s earmolds? Why?

Answer 26

Soft materials because they dont need to be replaced as often

Question 27

How does the earmold affect acoustics?

Answer 27

It modifies or “tunes” the HA response