Table 3.
Summary of electroacoustic characteristics of PSAPs and OTC devices based on published reports
| Characteristics | PSAPs (Smith et al17) | OTC hearing aids (Cheng and McPherson;24 Callaway and Punch;25 Chan and McPherson26) |
|---|---|---|
| OSPL90 | ||
| Peak frequency (Hz) | Not reported | 200–2,000 (1,400–2,000 more often) |
| Peak SPL (dB SPL) | Not reported | 105.6–133 |
| %THD | ||
| 500 Hz | 0–3.97 | 0.1–6.6 (outliers 15.6 and 23.5) |
| 800–1,000 Hz | 0.02–3.26 | 0.1–9.7 (outliers 30.0 and 46.5) |
| 1,600–2,000 Hz | 0–2.07 | 0.1–4.6 (outliers 10.1 and 10.8) |
| HFA FOG (dB) | Not reported | 2.4–52.8 |
| EIN (dB) | 23.85–54.48 | 19.8–52.9 |
| Frequency range (Hz) | Not reported | <200 (low) to 8,000 (high) |
| Battery life (hours) | Not reported | 37–194 hours |
Abbreviations: PSAPs, personal sound amplification products; OTC, over-the-counter; OSPL90, output sound pressure level for 90-dB input SPL; SPL, sound pressure level; THD, total harmonic distortion; HFA FOG, high-frequency average full-on gain; EIN, equivalent input noise.