Audiology and Otology

Stapes surgery for patients with otosclerosis who are six years old and older

Otosclerosis is a condition of the ear characterized by new bone forming in the joint space of the third bone of hearing, known as the stapes. When this happens, the stapes cannot move freely and the intensity of a sound wave is diminished, resulting in conductive hearing loss.

Stapes surgery helps resolve conductive hearing loss from otosclerosis. The surgery is conducted through the ear canal, where the stapes bone is replaced by a prosthetic hearing bone known as a piston. The piston is placed through a surgically created opening into the inner ear to bypass the joint space where new bone has formed. This allows free mobility of the hearing bones.

Outcomes from stapes surgery

The pure tone average (PTA) and individual change in air-bone gaps (ABG) were chosen as the standard measured primary outcome for stapedotomy. In the following graphs, a change in PTA indicates the effect of surgery on the patient’s average hearing levels across the range of hearing frequencies.

A change in ABG indicates the effect of surgery on the amount of conductive hearing loss at each frequency. Optimally, the ABG is less than 20 dB. When the ABG is 0 dB there is no longer any conductive hearing loss.

A clinically meaningful difference is considered 10 dB at each frequency for PTA and ABG changes.

Air-bone gap measurement at 500 Hz

Air-bone gap measurement at 1 kHz

Air-bone gap measurement at 2 kHz

Air-bone gap measurement at 4 kHz

Pure tone average

Cochlear implantation for patients with moderate-to-profound hearing loss and who are six years old and older

Cochlear implants are hearing devices for patients with moderate-to-profound hearing loss who do not benefit from a hearing aid. A cochlear implant has two parts: an implanted part and a processor.

The implanted part has a receiver stimulator and an attached electrode. The electrode is inserted into the inner ear (cochlea) and stimulates the cochlear nerve directly. During a cochlear implantation, a mastoidectomy is required to access the inner ear. On the outside of the head, the second part of the device, called the processor, uses a built-in microphone to detect environmental noises and relay electromagnetic sound signals to the inner, implanted part of the device.

Consonant-nucleus-consonant (CNC) are word lists and AzBio are sentence lists used to evaluate the speech perception abilities of hearing-impaired listeners and cochlear implant users. Improvements in CNC scores postoperatively above 50 percent indicate that a patient can communicate without completely relying on lip reading, sign or written communication.