Hearing Aids

Hearing Aids

What is a hearing aid?
A hearing aid is a personal amplifier that is recommended and fit according to your hearing loss and communication needs. Simply speaking, a hearing aid is a device that amplifies sounds, making them audible so that you can hear them better and more clearly. Most hearing aids now are digital which means there is computer technology and processing inside the hearing aid itself. If you are considering getting a hearing aid but are not sure how to begin we can help that process.

How do hearing aids work?
All hearing aids have 4 basic parts: a battery, a microphone, an amplifier and a speaker. Sound is picked up by the microphone and then sent to the amplifier where it is increased according to the wearer’s hearing loss. The amplified sound is sent to the speaker which sends this amplified sound into the ear. Digital hearing aids also have a tiny computer (digital processor) in the amplifier part of the aid.

Hearing Aid Technology:

  • Directional Microphones: Increases the sounds coming from in front of you while decreasing sounds coming from behind.  It is the only FDA approved feature to help you understand speech better in background noise.
    • Automatic Directionality- the hearing aid will automatically switch from amplifying all around you to just amplifying sound in front of you based on the noise level in your environment. This would be helpful in a restaurant or program where most of the “noise” would be coming from directly behind you.
    • Automatic Adaptive Directionality- Noise sources are not always stationary, and often, complex listening situations involve multiple noise sources that differ by frequency/pitch. Automatic adaptive directional systems are continuously tracking the noise source(s) and selecting the sound processing that gives you the best signal to noise ratio possible for any listening situation. This would be beneficial in social settings, at work, or anywhere where the “noise” could be moving around the room.
  • Noise Reduction Circuitry: Your hearing aid automatically adjusts gain, either in the low frequencies or for specific pitches when stead-state noises are detected.  This would help to reduce the amplification of sounds such as fans blowing or the hum of a refrigerator.
  • Channels or Frequency Bands: Speech and environmental sounds can be divided into frequency/pitch regions called channels or bands.  Sound in each region can be amplified or adjusted more of less independently of sounds in other regions.  The more channels available, the better the audiologist can fine tune your hearing aids to match your exact hearing loss, pitch by pitch.
  • Digital Feedback Reduction: Feedback is a squealing or ringing noise that can occur when amplified sound gets back into the hearing aid.  It can be annoying to the hearing aid wearer and to those around you.  Some hearing aids are able to monitor the presence of their own feedback and then reduce or eliminate the feedback through the use of a feedback cancellation system or notch filtering.  This is especially helpful for occasional feedback associated with jaw movements and close proximity to objects (the phone, collar of coat, hat).  
  • Telecoil: A magnetic induction coil inside the hearing aid picks up magnetic energy from a telephone or assistive listening devices.
    • Auto-Telecoil: The hearing aid will automatically switch to the telephone mode when magnetic energy from a phone is detected.
    • Binaural Phone: This feature wirelessly streams the signal from both land line and cell phone calls to both ears.  This feature may involve using an accessory device with Bluetooth technology also.
  • Bluetooth Connectivity: Bluetooth technology is a short-range, wireless interconnection between cell phone, computers and other electronic devices. Bluetooth technology allows your hearing aids to wirelessly connect to electronic devices through an accessory remote control. This means that speech and/or music signals from your television, phone, computer, MP3 player, etc., can be sent wirelessly to your hearing aids where you hear it is processed and amplified precisely for your hearing needs.
  • Binaural Connectivity: A wireless feature that allows a program or volume adjustment on one hearing aid to be automatically adjusted binaurally. This means that you can use one hand to adjust both aids simultaneously!
  • Speech Enhancement: Hearing aid automatically gives priority and enhancement to speech sounds and emphasizes the volume and frequency response for these sounds.
  • Frequency Transposition: This technology is for those individuals who have a severe to profound hearing loss in the high frequencies. High frequency information is processed by the hearing aid and placed at a lower octave to ensure that these key high frequency speech and environmental sounds are audible to the listener

Other Devices Available:

Osseo-integrated implants: These devices are approved for single sided deafness and conductive and mixed hearing losses.

  • Formerly known as bone-anchored hearing aids (BAHA).

Cochlear implants: These devices are approved for severe to profound hearing losses.

  • Med-el, Cochlear, and Advanced Bionics


Medical College of Wisconsin
8701 Watertown Plank Road
Milwaukee, WI 53226
(414) 955-8296
Directions & Maps
© 2017



Page Updated 09/07/2016