BioMed Research International / 2015 / Article / Tab 3

Research Article

Over-the-Counter Hearing Aids: A Lost Decade for Change

Table 3

Summary of the results of OTC hearing aids: 2-cc coupler measurements.

OTCOSPL 90 HFA FOG (dB) Frequency range (Hz) EIN (dB)THD (%) Battery life (hours)
Peak frequency (Hz)Peak SPL
(dB SPL)
500 Hz800 Hz1.6 kHz

A tone N1600127.644.0375–400028.41.9N/A0.4DNT
A tone L1600128.539.7667–466728.5N/AN/A0.7DNT
B700129.829.0354–>800035.20.30.10.7DNT
C tone N1400126.652.8<200–366726.42.3N/A0.1DNT
C tone H1400126.352.5<200–366725.52.4N/A0.3DNT
C tone L1400126.141.8396–366729.73.33.10.1DNT
D1400129.337.2<200–366730.62.11.20.5142
E1700118.819.1<200–466738.14.2N/A0.1182
F1400125.932.6<200–383324.91.4N/A0.3233
G1600126.830.6<200–533333.22.7N/A0.2235
H800124.414.2<200–433345.66.61.210.1307
I2000113.120.9<200–500031.423.546.510.8154
J700118.47.6<200–466752.94.80.84.6212

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.