CROS or BiCROS

by: Dr. Frank Shepel, Au.D.
SoundPoint Audiology and Hearing Center
Casa Grande, AZ

Are These Hearing Aid Options Right For You?

What are CROS and BiCROSS hearing aids?
CROS stands for contralateral routing of signal and BiCROS is the acronym for bilateral routing of signal.

What type or degree of hearing loss utilizes these styles?
These hearing aids are utilized when a hearing impaired individual has normal to moderate hearing loss in one ear and no usable hearing in the other ear. This would be what could be called a “dead” ear or one where amplification would not provide any significant benefit to an individual’s ability to understand speech or one where due to surgery or some other medical condition a hearing aid should not be fit to that ear per a physician’s recommendation.

How do these hearing aids work?
Two units are utilized to get the sound signals to the better hearing ear.  A transmitter unit with a microphone is worn on the ear with no usable hearing.  On the better hearing ear a hearing aid with a receiver is worn.  In the CROS hearing system, sound from the poorer hearing side is fed across the head to the better hearing ear.  This provides sound to the better ear which is generated from the poorer hearing or off side.  This would allow a person with no useful hearing in their right ear to hear conversations better while driving a vehicle as the passenger’s voice would be transmitted to their good ear which is closer to the driver door window.  In this case the driver would not need to remove their vision from the road to look at the talker to understand a conversation.  In the BICROS hearing system we have one ear that cannot be helped and another ear that hears but not too well so it needs help to hear better also.  With a BICROS set up, sound is sent from the poorer hearing ear transmitter’s microphone across the head to the better ear which has the receiver.  The receiver picks up the sound from the transmitter and amplifies it as well as the sound from the receiver side microphone. This allows the user to hear sound from the off poorer side and sound from the better side more efficiently.  Sound is thus amplified on both sides and put into the better ear.

CROS: normal hearing in better ear – no hearing or unaidable hearing loss in the poorer ear
BiCROS: aidable hearing loss in the better ear – no hearing or unaidable hearing loss in the poorer ear

How long have these systems been available?
CROS and BiCROS hearing aids have been available since the 1970’s.  At that time the user needed to have a wire running from one ear to the other to carry the signal across the head.  A popular way of doing this was to hide the wire in the frames of the individual’s glasses.  The hearing aids were then contained in the bows of the glasses.  A consequence to this was that the glasses were physically large to house all the components and they were difficult to fit as much care needed to be taken when bending them to fit each individual.  The units also tended to have more breakdowns due to the nondigital technology needing many wires in the circuitry.  Also, when an individual removed their glasses their hearing aids came off.  In colder climates like Minnesota and North Dakota where I worked at the time, when a person walked into a store in the winter their glasses would fog up and need to be removed, so then it became difficult to communicate with the clerk until the fog was removed and the glasses reattached.  If glasses were not worn, a wire was worn behind the head connect the transmitter and receiver sides of the hearing aids.  Hopefully, it could be hidden in the individual’s hair which was much easier for the females.

How have these systems improved?
Today these systems have gone wireless removing the need to have a wire running from one ear to the other.  The transmitter unit broadcasts the sound picked up by the microphone on the poorer hearing side to the receiver antennae in the receiver unit on the better hearing side.  This has made them much more comfortable and easier to wear. They are available as custom in the ear products or the more popular over the ear style. Today the CROS/BiCROS systems have also left the analog age of technology and converted to digital circuitry.  This is a significant change as in the past, individuals needing to utilize these instruments had to settle for second class technology because digital was not available for them to provide more noise reduction, better understanding and more adjustability.  With the new digital wireless devices users will be able to utilize the best technology available or the same technology that others are able to purchase.

Are CROS/BiCROS hearing aids difficult to get accustomed to?  
Not any harder than relearning to hear with any other type of hearing aid.  The individual does need to relearn how to hear and they still may want to turn their head at first when someone is talking on their poorer hearing side.  With these units, individuals will still note that directionality, the ability to tell from where sound is originating does not improve.  We need to be able to hear with both ears to have direct finding ability for hearing.  With these aids, even though hearing is provided from the poorer side, all hearing is being done with a single, better ear not with two separate ears.

Are these aids more expensive?
I like to think of these styles as having 1 ½ hearing aids versus 2.  They are typically more expensive than one but less than buying two.  With this type of hearing aid it is better to get the higher technology levels of hearing aid because the wearer is using only one ear to do all their hearing and the better technology gives them better hearing through more noise reduction, better fitting to their hearing loss, more adjustability for fine tuning and better understanding through faster more effective processing of the sound signal.  All these benefits lead to better understanding and more efficient communication ability which is what we want from hearing aids.

All American Hearing is proud to announce the release of our new Pride i2400 CROS/BiCROS RIC style hearing aids.  These digital units have dual core quad processor technology for digital enhancement of the incoming signals providing  significant improvements in speech quality and understanding, background noise reduction and music listening appreciation all contained in a small over the ear instrument. Pride is compatible with the wireless SurfLink accessories and provides improved phone conversations with ear to ear streaming.

Benefits of Pride Technology

  • Clearer and easier conversations with precise speech audibility and accurate speech detection in difficult listening situations
  • Better understanding in noise
  • Wind, noise, whistling and feedback management for optimal speech understanding
  • Wireless functionality
  • On board volume control
  • Simultaneous processing of multiple sounds for a comprehensive listening experience that makes speech crisp and clear while keeping ambient noise natural
  • Improved phone conversations with ear to ear streaming
  • Customizable tinnitus relief with our Multiflex Tinnitus Technology

If you or a loved one feels that you are in need of hearing help, please contact our office today to set up a consultation and a 30 day trial to experience what improved hearing can do for your quality of life!

Franklin A. Shepel, Au.D
Board Certified Doctor of Audiology

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