Although 8.9 million American households are home to at least one person who is completely deaf in one ear, a recent study shows that a third of them have not sought treatment. This finding raises questions about how many Americans suffering from Single Sided Deafness (SSD) go undiagnosed.

The study further revealed that while one out of every four people knows someone suffering with SSD, the same proportion says that person has not sought treatment.

"Single Sided Deafness is difficult for patients, but there are things we can do to help alleviate the problems associated with SSD," said Richard Chole, MD, chief of otolaryngology at Barnes-Jewish Hospital and Washington University School of Medicine.

To help many of those suffering from SSD, Dr. Chole and his team use a device called BAHA. It''s an implantable bone conduction hearing device that treats people who may not benefit from or even be able to use a hearing aid. That includes people suffering from SSD -- which can result from head trauma, viral infection, or acoustic neuroma tumor surgery -- as well as people with conductive and mixed hearing loss from conditions such as perforation of the middle ear (chronic suppurative otitis media), ear canal infection (otitis externa), and blockage or absence of the ear canal (ear canal atresia).

The BAHA system is implanted during a short outpatient surgical procedure and is worn by approximately 18,000 people worldwide with an excellent success rate.

The BAHA system works through direct bone conduction, using bone as a pathway for sound to travel to a functioning inner ear (cochlea), bypassing the outer and middle ear.

"The procedure takes about 45 minutes in the outpatient operating room and the patient goes home the same day," says Dr. Chole.

In BAHA system treatment, sound is transferred from a removable sound processor via an external abutment connected to a small titanium fixture implanted in the skull bone behind the ear. In this way, the vibrating transducer inside the sound processor is directly connected to the skull of which the inner ear is an integral part. Placing a fixture and an abutment in the skull bone is a minor surgical procedure and is done under general or local anesthesia.

"Very often the device recedes into the hairline and no one can tell the device is even there," says Dr. Chole.

The BAHA system is cleared by the FDA for use in the United States to treat mixed and conductive hearing loss, as well as SSD.