MinusNine miniature, inductively-coupled wireless earphone

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 data systems in vehicles, TDMI noise from TETRA terminals and Cellphones as well as mains-borne noise from electric motors, neon signs and power lines. A full range of compatible neckloops, shoulder loops and brooch inductive transmitters is available to operate with the MinusNine wireless earphone.

  • Frequency Range: 300-3000Hz
  • DSP Type: Digital Hybrid, DSP and EEPROM with custom Firmware & Software
  • Distortion: <10% @ 1kHz
  • Receiver: Magnetic moving armature
  • Max Output Sound Pressure Level (2cc coupler) @1kHz:96dB ±2dB 
  • Quiescent Noise Control (no audio input): Soft Squelch. Hard Squelch option
  • Quiescent Noise (Soft Squelch): 35dB (With hard squelch option quiescent is silent)
  • End of Battery Life: Audible Beep
  • Battery: 1.4 VDC A10 Zinc Air or Equivalent
  • Minimum Operating Voltage: 1.1 VDC
  • Typical Battery Life (A10 Zinc Air):>50 hours
  • Sensitivity (Standard): 75dB@1kHZ ±3dB/10mA/M
  • Size: Nominal max, Length:15mm x Width:8mm
  • Weight (including battery): 1.75 grams inc. battery
  • Operating Temperature Range: -10°C to +40°C
  • Cerumen Filter Type: Replaceable Mesh Filter
  • Colour Options: Beige, Mid Brown, Dark Brown
  • Custom Fit Option: Available at additional charge.

It’s coming. Please refer to sales office.

Wireless Earpiece Accessories



Inductive neckloop with sensitive integral microphone for VSB and basebad wirleless earphones


Inductive brooch for baseband wireless earpeices


Shoulder Pad

Inductive shoulder pad with sensitive integral microphone for VSB and basebad wirleless earphones


Seat Pad

Inductive seatpad VSB and basebad wirleless earphones



Replacement HF3 ear-wax guards for all Sensorcom wirless earphones. BeanBugs need HF4


A10 Zinc Air Batteries

We recommend Rayovac ZincAir batteries to give Sensorcom wireless earphones optimum performance


Hygiene/Fit Sleeves (4 sizes)

Soft PVC sleeves to assist the fit and security of wireless earphones

Vehicle Loop Amplifier

Vehicle loop amplifier that will support baseband and VSB wireless earphones. Wide DC voltage operating range: 4 – 20 VDC.


Vehicle Roof Loop

Cable loop designed and optimised for inseting into the roof of vehicles


Spring-top Storage Pouch

Spring top storage pouch for wireless earphones, batteries etc.