Patients with microtia and atresia normally have an intact inner ear. As a result of the malformation a pure conductive hearing impairment occurs with a hearing loss between 60 to 70 dB or 75%. If both ears are malformed, the childÔÇÖs speech and general development are severely affected. As a result, from the age of 2 to 4 they need definitive hearing rehabilitation, after they have worn a headband hearing aid in the first years of life.
We also recommend early definitive hearing rehabilitation for single-sided deafness in order to facilitate directional and genuine binaural hearing. Binaural hearing enables good speech understanding even in difficult listening situations, such as in classrooms.
Which treatment is suitable for a patient is only decided after extensive examination and a detailed consultation.
Middle Ear Reconstruction
If the necessary anatomical prerequisites exist, the ear canal can be enlarged and the ear drum or middle ear can be reconstructed. Autologous materials (the patientÔÇÖs own cartilage or tissue) and titanium implants are used for this. In this way we can restore the transmission of sound which was previously blocked. The anatomical prerequisites are checked using a CT scan. The necessary prerequisites include, among others, an existing ear canal, even if it is narrow with a malformed middle ear. Completely blocked ear canals can likewise be reconstructed. The results here, however, are often unsatisfactory in the long term.
Bone Conduction Implants
The common factor in all bone conduction hearing devices is that they convert sound into vibrations (with what we call a signal transducer) and send these to the skull. The skull then conveys the vibrations to the intact middle ear. The sound transmission always takes place in both ears and therefore, in this instance, directional hearing is not possible as it is in true binaural hearing.
Hearing devices can be divided into different groups based on their technology.
Group 1: (For example COCHLEAR Baha┬«, OTICON Ponto┬«)
The hearing device is located with the signal transducer outside the body and attached by a rigid coupling to the skull.
Group 2: (For example COCHLEAR Baha Attract┬«, MEDTRONIC SOPHONO Alpha┬«)
The hearing device is also located outside the body together with the signal transducer. The transmission of the vibrations however takes place using two magnets through intact skin.
Group 3: (For example MED-EL Bonebridge┬«)
Only the hearing device is located outside the body. The signal is conveyed to the skull by an implanted signal transducer. This converts the signal directly into vibrations.
Active Middle Ear Implants
The active middle ear implant is considered particularly effective. The prerequisite for implantation depends however on the severity of the malformation and the age of the patient.
Active middle ear implants convey sound directly to the intact inner ear. In this instance they are coupled to the stapes, the innermost of the little bones in the ear used for hearing known as the ossicles. Consequently, sound is only transmitted to the ear of the affected side and true binaural hearing is possible.
Active middle ear implants have an external audio processor which conveys a signal to the implanted signal transducer. The signal transducer is so small that there is room for it in the malformed middle ear (for example MED-EL Vibrant Soundbridge┬«).