Figures for Chapter 15

Special issues for children

Dillon (2001)

Hearing Aids

Figure 15.1 A Huggie AidTM attached to a BTE hearing aid.

Aid retention

Source: Dillon (2001): Hearing Aids

Figure 15.2 Cross section of a hollow-concha earmold.

Hollow-concha earmold

Source: Dillon (2001): Hearing Aids

10

15

20

25

0 5 10 15 20 25

Age of child (months)

Leng

th o

f ear

can

al (

mm

)

Figure 15.3 Typical length of the ear canal as a function of age (Keefe et al, 1994). Solid line is a smooth curve fitted to the data and dashed line shows the average length of the adult ear canal (Keefe et al., 1994; Salvinelli et al., 1991).

Ear canal length

Source: Dillon (2001): Hearing Aids

0

5

10

15

20

100 1000 10000Frequency (Hz)

RE

CD

re

adul

t val

ues

(dB

)

1

3

6

12

4824

Figure 15.4 The increase in SPL generated by a hearing aid in an average child's ear relative to that in an average adult's ear. Children are aged from 1 to 48 months, as indicated for each curve.

RECD relative to adults

Source: Dillon (2001): Hearing Aids

Too loud

Loud

Just right

?

Too soft

Figure 15.5 Verbal and pictorial loudness categories used for evaluation of loudness comfort and discomfort while wearing hearing aids.

Loudness discomfort rating scale

Source: Dillon (2001): Hearing Aids

Development of expressive and

receptive language

Hearing aids are fitted early and well

Hearing aids are consistently used

Hearing aids continue to operate properly

Child receives stimulating auditory

input

Parents have good understanding and are

highly motivated

Figure 15.6 Goals of the hearing habilitation process, culminating in maximal development of language.

Habilitation goals

Source: Dillon (2001): Hearing Aids