The MinusNine is a miniature, inductively-coupled wireless earphone utilising an advanced digital microelectronics platform running custom software. It produces outstanding speech quality, reduced interference levels, precise output level control and is anatomically profiled to fit deep into the ear canal making it discreet, secure and usable in the left or right ear. Special functions include soft squelch, automatic gain control and low battery alarm. The MinusNine is robust and designed to operate in hostile environments and incorporates a hygienic user-replaceable cerumen (earwax) filter system. Design emphasis has been placed on its ability to suppress interference, typically generated by cellphones, dimming systems and other sources of RF spectrum noise.
Frequency range: 300-3000Hz. Maximum output: 96dB SPL +/-2dB, 1kHz, measured on 2cc coupler. Sensitivity: 75dB SPL +/-3dB, 1kHz, for 10mA/metre. Quiescent noise: Less than 35dB.
Battery: A10 Zinc Air or equivalent. Typical battery life better than 50 hours. End of battery life indicated by audible beep.
Dimensions: 15mm(l) x 8mm(w). Weight (including battery): 1.75g.