It's no secret that our world is getting louder and more chaotic. From
Individuals who have normal to moderate hearing loss in one ear and no usable hearing in the other ear might be helped by a “CROS” (contralateral routing of signal) or “BiCROS” (bilateral routing of signal) hearing instrument. By using a transmitter unit with a microphone that is worn on the ear with no usable hearing, sounds are gathered and channeled to the better ear, which is outfitted with a hearing instrument with a receiver. This way, the CROS hearing system feeds the sound from the non-hearing side to the better ear. With a BiCROS system, sound is sent from the non-hearing ear to the other ear, which hears but also needs amplification to overcome a degree of hearing loss.
P.S. Both CROS and BiCROS systems enable users to hear sounds from the non-hearing sides of their heads that might otherwise have gone unnoticed.