What are CROS Hearing Aids?

Hearing aids are complex electronic devices. Depending on the hearing aid, there may be digital amplifying chips, noise reduction technology, and orientational microphones. At the most basic level, hearing aids utilize the advanced technology to give those with hearing impairments a helping hand. One specific device, a CROS hearing aid, makes up a special subset of hearing aids.

Contralateral routing of signal amplification system, otherwise known as a CROS hearing aid, works differently than a standard hearing aid. Individuals who have a hearing impairment in one ear but generally good or unimpaired hearing in the other ear wear make up the users for this special category.

Often, these individuals have SSD—single-sided deafness, where one ear has little to none hearing in one ear. Not everyone will benefit from CROS hearing aids, as they work differently than normal in-the-ear or behind-the-ear hearing aids.

How Does CROS Hearing Aid Work?

cros hearing aids in use

A user who needs hearing in one ear, but not the other, often chooses to use CROS hearing aids due to their functionality. CROS hearing aids work by picking up surrounding sounds via a microphone on one hearing aid and transmitting the sound to the other hearing aid. As two hearing aids are needed for the system to work, the user must wear two hearing aids. On the bad, hearing-impair ear, the user will wear the hearing aid with a microphone to pick up the sound they’d normally miss. All the noises and sounds are then transmitted to the hearing aid worn on the good, non-impaired ear.

The idea is for users who have trouble hearing in one ear to, in a sense, regain that hearing by using a microphone. For example, if someone was in a position where the sound primarily came from their bad ear side, the wearer could still hear through the help of the CROS hearing aid. A user who is driving, but cannot hear sounds out of their left ear may greatly benefit from having a microphone on their left side.

CROS Hearing Aid Pros and Cons

The first and most important benefit to wearing CROS hearing aids is the confidence it returns to the wearer. Often, individuals with hearing loss in one ear may struggle to participate in social activities and events where their hearing is tested. Wearing CROS hearing aids allows individuals to recover the hearing in their impaired ear giving them confidence and ending any feelings of isolation they may have had.

The biggest downfall of CROS hearing aids, as reported by users, is the fact that they simply amplify all surrounding noises. CROS hearing aids do no separate, filter out background noises, and amplify only specific frequencies. Because of this, it can prove cumbersome for individuals to mentally parse the different noises. Thus, wearers may struggle to hear voices or other desired sounds in an area with many loud noises.

Below, we have listed a set of pros and cons based upon an abundance of CROS hearing aid reviews.


  • All noise is amplified dramatically
  • Synthetically recovered functionality of the hearing-impaired ear
  • Users can have an increased ability to determine where noises originated
  • Many CROS aids have wi-fi capability
  • Increased confidence for wearers
  • Assists individuals where standard hearing aids cannot
  • Generally cheaper than other alternatives


  • Wearers of CROS hearing aids and tinnitus impacted individuals will not see improvements in their condition
  • Background noises become amplified causing disturbance and distraction
  • Requires fitting by an audiologist
  • The sounds may prove tough to adapt to for some wearers
  • The impaired ear gets no direct stimulation

Leading CROS Hearing Aid Providers


Signia has created a CROS hearing aid solution that connects to various, nearly invisible hearing aids. The Signia CROS Pure Transmitter uses new in-house technology that identifies speech, isolates it, and amplifies it. As seen above, previous CROS system users were unable to differentiate sounds well, but that has all changed.

Signia’s CROS Pure Transmitter features directional microphones, a miniReceiver, and a wireless data exchange system for energy-efficiency. Furthermore, this device has an IP67 rating meaning it is resistant to sweat, dirt, dust, and moisture.


Another leading brand for CROS systems, Phonak has created the CROS II. This device automatically detects the wearer’s environment and adjusts listening modes to fit it. Like the previous CROS system, the CROS II zooms in on voices in front of the wearer to enhance listening capabilities.

The Phonak CROS II has a volume control button, extended battery life, and a discreet style. The CROS II is built as an easy-to-use device to improve the lives of those struggling with SSD.

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