The aim of this study is to compare speech perception in noise with one activated Osia (unilateral) versus two activated Osia (bilateral), in children with high grade microtia/ear atresia fitted with bilateral Osia implants. In order to do these measurements, the enrolled children will get OSIA implants on both sides during a standard surgery procedure. Six months following the implantation, audiologist testing will be done with one implant active compared to both.

High grade microtia corresponds to a congenital malformation of the pinna and the external auditory meatus associated with a malformation of the middle ear. Ear atresia a congenital malformation of the external auditory meatus and middle ear, associated to a normal or near norma pinna.

In the case of hearing loss related to high grade microtia or ear atresia, be the type of hearing rehabilitation cannot be achieved with conventional air-conduction hearing aids, due to the absence of an ear canal. Different options are available and reimbursed by French medical insurance system. The Cochlear Osia implant is a semi-implantable bone conduction hearing aids. It is an active, transcutaneous (closed-skin) implant, which has the CE mark and is covered by the Health Insurance Fund for adults.

When deafness is bilateral and unaided, it impacts the development of oral language, daily life, and academic progress. Studies also show that speech perception in noisy environments is impaired. This can be very disabling, especially for young school-aged children. There are also studies showing that sound localization is improved when using two hearing aids.

Although bilateral fitting has benefits, bone conduction hearing aids are not always surgically placed bilaterally in children with ear aplasia and no clinical research has yet been conducted with the OSIA system. The objective of this study is to evaluate the effectiveness of bilateral implantation of the Osia System in children with high grade microtia or ear atresia.

Once the implantation surgery is done, the patient will come back for at least three visits: two adjustment visits, 1 month and 5 months afterwards, and two ENT consultations at 1 month and 6 months. These visits are part of the usual follow-up for children with bone conduction implants. Experimental audiological measurements will be carried out at the 6-month visit.

Inclusion Criteria:

• To be aged between 7 and 17 years old at the time of enrolment
• Use spoken French as primary mode of communication
• Diagnostic of moderate to severe bilateral high grade microtia and/or ear atresia resulting in conductive hearing loss with an ACPTA between 60 and 80 dB and a BCPTA between 0 and 20 dB
• Fitted with a unilateral or bilateral headband/headband/adhesive bone conduction device for more than 12 months.
• In case of microtia: after or before ear reconstruction planned using the conventional costal cartilage graft procedure; anatomical conditions allowing implantation of the OSIA outside the area of a future ear reconstruction.
• To be a medical and audiological candidate for the OSIA system
• To be affiliated with a health insurance plan or be eligible for it
• Signed consent from the legal guardian(s)

Exclusion Criteria:

• Weight less than 7 kg (CE marking limit)
• Diagnosed with a severe neurological condition, identified by an MRI and/or a neuropediatric assessment
• Diagnosed with a severe cognitive impairment, child psychiatric impairment, or developmental delay
• Diagnosed with a severe cochleovestibular or cochlear nerve malformation
• Live in a social context that does not allow for long-term follow-up
• To be part of a family that does not understand spoken French
• Already equipped with one (or two) bone conduction implant(s)
• Affiliated with minimum state healthcare (AME)
• To currently be pregnant or breastfeeding