Hearing Device Options
Hearing Loss in CAAM:
In almost all cases of Congenital Aural Atresia and Microtia (CAAM), the inner ear is normally formed, and the hearing nerve function is present. The hearing loss associated with CAAM is produced by the lack of an ear canal and eardrum and can be ‘bypassed’ with vibrations in the bone surrounding the inner ear, which in turn stimulates the hearing nerve. Normal sound thresholds and quality are possible with these technologies. The bone can be stimulated with implanted abutments, vibrating internal devices, vibrating magnets, or even via connecting a vibration-producing dental appliance to a tooth. At times, this technology is used temporarily until an ear canal can be constructed, and in other cases, bone conduction can be used throughout life to provide a hearing solution.
Non-Surgically Implanted Bone Conduction Hearing Devices
Surface Bone Conduction Devices are non-surgically implanted hearing devices that are worn on a headband or other apparatus and serve to provide sound stimulation in the absence of an ear canal. In general, these hearing devices receive sound with a microphone and convert the signal into vibrations, which are transmitted by the device through the bone of the skull. With these vibrations, the inner ear can be stimulated, allowing the patient to hear when the normal channel of the ear canal is not present. In this fashion, sound waves can bypass the congenital lack of an ear canal and eardrum and stimulate the normally functioning hearing nerve directly.
These devices can be used from several months of age onward. The hearing received may allow for normal speech, language, and brain development. Some children use this technology until an ear canal is made, while others continue to use this technology throughout life if they are not good candidates for the creation of an ear canal. In patients who are candidates for canalplasty, reconstruction is strongly recommended over implantable bone conduction devices, as the sound quality and function is superior to implanted devices. However, in patients who are not candidates for canal reconstruction, implantable devices offer an excellent alternative to improve hearing.
Examples:
Soft Band BAHA: For more information about the BAHA, please visit: Cochlear Website
Ponto: For more information about the Ponto, please visit: Oticon Website
Surgically Implanted Hearing Devices:
With implantable bone conduction devices, a surgically implanted abutment is placed in the bone behind and above the ear and allowed to heal for several weeks to months. After healing, an external processor that receives sound is fitted and programmed by an audiologist to optimize the patient’s hearing. With this system, the external processor receives sound, converts it into a vibration, and then transmits it to the surgically implanted portion. These vibrations are transmitted through the bone of the skull to the inner ear, allowing stimulation of the hearing nerve.
There are now numerous types of implantable bone-conduction hearing aids on the market, including but not limited to the following devices: