Microphone-in-helix (MIH)

Microphone-in-helix (MIH) hearing aids have the microphone located outside of the hearing aid shell and inside the top fold of the external part of your ear (cymba concha). The shell itself is available in various sizes and fits into the lower part of your external ear (cavum concha) like a completely-in-canal (CIC) or in-the-canal (ITC) hearing aid.  The microphone and shell are connected by a discreet ‘mictube’ which houses an electrical cable. Extraction cords can be fitted to ITE hearing aids to help insert and remove them from the ear.

microphone-in-helix-small_mih-s_hearing_aidReSound LiNX2On earcicside

Hover over to view MIH when worn

MIH hearing aids house either a size 10 (Yellow), size 312 (Brown) or size 13 (Orange) battery depending on the size shell selected. The typical lifespan of a size 10 battery is between 3-5 days, size 312 battery between 5-7 days and size 13 battery between 10-14 days but this can vary depending upon the number of hours per day the hearing aid is worn, the severity of hearing loss and the technology level of hearing aid.

Benefits

  • Since the microphone is located outside the shell it can be manufactured much smaller than a standard ITC.
  • The extra space created inside the shell can be used to insert an ultra-power receiver making the MIH one of the most powerful custom hearing aids available.
  • The position of the microphone also helps to:
    • preserve the natural acoustics provided by the external part of your ear (pinna)
    • minimise the effects of wind-noise.
    • significantly reduces the likelihood of feedback (e.g. whistling) since the microphone is not in close proximity to the receiver
  • Ideal for somebody who has limited dexterity and reduced vision.
  • Wireless and telecoil options
  • Increased surface area means they are less likely to:
    • feedback (e.g. whistle) due to acoustic leakage
    • work loose whilst talking and chewing, especially if you have a straight and inclined ear canal shape.

Limitations

  • Telephone receiver needs to be held in slightly unnatural position over the microphone in the top fold of the externa ear.
  • Require more maintenance and are more susceptible to damage due to ear wax and dead skin ingression inside the microphone port
  • The mictube is phone to losing its shape, developing kinks and disconnect itself from the shell.
  • As with all custom hearing aids, MIH hearing aids may need to be ‘re-shelled’ from time to time since the ear canal cartilage can change shape and size. This is not covered under the warranty and will require new ear impressions.

Other hearing aid styles…