CROS and Baha-Which Type of Hearing Assistance Is Better?

The system confers sensitive hearing afforded by an efficient connection to the temporal bone, said Dr. Niparko. Because the cochlea is rigidly ensconced in the temporal bone, vibrations are faithfully conveyed to it, he explained.

Baha was originally indicated for hearing losses not amenable to conventional amplification, including mixed losses due to chronic infection, inoperable otosclerosis, and atresia of the ear canal or middle ear mechanism, said Dr. Niparko.

In these cases, the ear that has the hearing loss receives the Baha, explained Gail Murray, PhD, Director of Audiology Services and Clinical Director of the Cochlear Implant Program at the University Hospitals Case Medical Center in Cleveland, Ohio.

In 2002, the FDA approved Baha for use in patients with unilateral sensorineural hearing loss. Currently, the most common Baha indication is for patients with single-sided deafness who don’t benefit from a hearing aid on the side of impairment, noted Dr. Murray.

If, for example, a patient loses hearing in the left ear due to a brain tumor being removed or an infection, Baha can be implanted near the left ear and carry sound vibrations through the skull directly to the right ear’s cochlear nerve, explained Dr. Kohan. There’s no loss of energy of vibrations, he said. It’s an efficient way to transmit sound to the cochlea.

CROS Advantages

The advantage of traditional and transcranial CROS is that they both transmit sound from the bad ear to the good ear without requiring surgery, noted Dr. Kohan, adding that traditional CROS has been the workhorse of hearing aids for decades.

People who have contraindications for surgery might benefit from a CROS system, said Dr. Wazen. Although surgery for Baha is minimal, some patients prefer nonsurgical options, he said.

Another advantage of both traditional and transcranial CROS is that patients can remove these devices and use them when they want, said Dr. Kohan.

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Figure. What’s that you say? Both Baha and CROS have advantages and disadvantages, but Baha seems to have an edge due to better hearing quality and patient comfort.

Baha Advantages

Although CROS doesn’t require surgery, Baha tends to have a high level of user satisfaction, said Dr. Niparko. Bone-conducted hearing seems to transfer sound across the skull in a narrow but useful band within the sound frequencies occupied by many consonants, he said. This creates a useful filter that appears to allow for access to speech sounds from the hearing-impaired side but limits noise inputs from that side, he explained.