Over-the-Counter Hearing Aids: A Lost Decade for Change
Table 3
Summary of the results of OTC hearing aids: 2-cc coupler measurements.
OTC
OSPL 90
HFA FOG (dB)
Frequency range (Hz)
EIN (dB)
THD (%)
Battery life (hours)
Peak frequency (Hz)
Peak SPL (dB SPL)
500 Hz
800 Hz
1.6 kHz
A tone N
1600
127.6
44.0
375–4000
28.4
1.9
N/A
0.4
DNT
A tone L
1600
128.5
39.7
667–4667
28.5
N/A
N/A
0.7
DNT
B
700
129.8
29.0
354–>8000
35.2
0.3
0.1
0.7
DNT
C tone N
1400
126.6
52.8
<200–3667
26.4
2.3
N/A
0.1
DNT
C tone H
1400
126.3
52.5
<200–3667
25.5
2.4
N/A
0.3
DNT
C tone L
1400
126.1
41.8
396–3667
29.7
3.3
3.1
0.1
DNT
D
1400
129.3
37.2
<200–3667
30.6
2.1
1.2
0.5
142
E
1700
118.8
19.1
<200–4667
38.1
4.2
N/A
0.1
182
F
1400
125.9
32.6
<200–3833
24.9
1.4
N/A
0.3
233
G
1600
126.8
30.6
<200–5333
33.2
2.7
N/A
0.2
235
H
800
124.4
14.2
<200–4333
45.6
6.6
1.2
10.1
307
I
2000
113.1
20.9
<200–5000
31.4
23.5
46.5
10.8
154
J
700
118.4
7.6
<200–4667
52.9
4.8
0.8
4.6
212
Note. Peak SPL: peak sound pressure level; N/A: not applicable. According to the 12 dB rule, THD does not need to be measured at that frequency when its second harmonic was amplified 12 dB more than the first harmonic in the frequency response curve (Frye, 2010 [20]). DNT: did not test. Measurement of battery current drain was not conducted since no battery substitution pills for AA and AAA battery size were available.
