Transcript 15 special hearing aid issues for children

Figures for Chapter 15
Special issues for children
Dillon (2001)
Hearing Aids
Aid retention
Figure 15.1 A Huggie AidTM attached to a BTE hearing aid.
Source: Dillon (2001): Hearing Aids
Hollow-concha earmold
Figure 15.2 Cross section of a hollow-concha earmold.
Source: Dillon (2001): Hearing Aids
Length of ear canal (mm)
Ear canal length
25
20
15
10
0
5
10
15
20
25
Age of child (months)
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).
Source: Dillon (2001): Hearing Aids
RECD relative to adults
RECD re adult values
(dB)
20
1
15
3
10
6
12
24
48
5
0
100
1000
10000
Frequency (Hz)
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.
Source: Dillon (2001): Hearing Aids
Loudness discomfort rating scale
Too loud
Loud
Figure 15.5 Verbal and
pictorial loudness
categories used for
evaluation of loudness
comfort and discomfort
while wearing hearing
aids.
Just right
?
Too soft
Source: Dillon (2001): Hearing Aids
Habilitation goals
Hearing aids are
fitted early and well
Parents have good
understanding and are
highly motivated
Hearing aids are
consistently used
Hearing aids continue
to operate properly
Development of
expressive and
receptive
language
Child receives
stimulating auditory
input
Figure 15.6 Goals of the hearing habilitation process, culminating in maximal
development of language.
Source: Dillon (2001): Hearing Aids