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 |
|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|
|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|
|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 ).|
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.