Congenital malformations of the ear include malformations of the outer ear, middle ear and inner ear. In terms of embryological development, the outer and middle ear development have the same origin, while the inner ear development originates from different progenitors, so that the outer ear malformation rarely occurs simultaneously with the inner ear malformation, but is often accompanied by the middle ear malformation. Therefore, this article focuses on congenital external ear malformation with or without middle ear malformation, which is usually clinically referred to as congenital microtia, and the reconstruction of hearing in this type of disease. The prevalence of congenital microtia is about 1s6000 to 1s6830. Clinically, congenital microtia is characterized by various degrees of developmental malformations of the auricle, narrowing or atresia of the external auditory canal, often accompanied by developmental malformations of the middle ear, and abnormal development of the tympanic chambers and the auditory tuberosities can be seen on high-resolution CT of the temporal bone, while inner ear malformations (mostly occurring alone and manifesting as sensorineural deafness) are less common. The audiological diagnosis of microtia is mostly conduction deafness. There is no consensus on the surgical treatment of unilateral congenital microtia, and some scholars believe that unilateral microtia should be operated on at a later date, until adolescence or adulthood. Hearing loss in children with bilateral microtia is often characterized by permanent air-conduction hearing loss, which affects speech and communication due to poor hearing. In addition, the lack of an auricle and external auditory canal makes it impossible to wear conventional air-conduction hearing aids. However, fortunately, children with bilateral microtia can still obtain better speech perception and recognition through hearing reconstruction methods due to normal inner ear function and normal or near normal bone conduction hearing. Hearing reconstruction methods: 1. Implantable bone-conduction hearing devices This type of device allows the patient to hear sound by directly vibrating the skull and transmitting the sound to the inner ear through the bone-conduction pathway. They require surgical implantation and have certain requirements for the age of the child. Those who are too young cannot undergo surgery due to insufficient cranial development, and generally need to be around 6 years old to undergo such surgery. For children younger than 6 years of age who cannot receive implantable bone-conduction hearing devices, they can wear a softband bone-conduction hearing aid early in the transition and wait until they are age-appropriate to undergo implantation. Common products used in clinical practice to treat these conditions include the BAHA hearing implant system in Australia, the Bone Bridge hearing implant system in Austria, and the Ponto hearing implant system in Denmark, all of which are equipped with softband bone-conduction hearing aids for younger children. Some studies have shown that softband BAHA can be worn as early as 3 months of age. A study on the level of language development in children with bilateral congenital external auditory atresia who applied softband BAHA showed that the development of language comprehension and expression was normal until 30 months of age and below normal at 30-46 months. In addition, their speech development showed significant progress after bilateral hearing improvement with BAHA. Therefore, wearing a softband BAHA during infancy can meet the most basic speech development needs, but after 3 years of age, the child will have higher hearing requirements in order to understand more complex language, and the hearing improvement of implantable BAHA is about 15dB higher than that of softband BAHA, so it is recommended that the child replace the implantable BAHA after reaching a certain age to adapt to the higher hearing requirements. 2.Middle ear implantable hearing aid The principle of middle ear implantable hearing aid is: the sound is collected and coded by the speech processor and sent to the implant, the sensor of the implant produces vibration according to the received signal, and after the vibration is conducted to the inner ear, the patient hears a clear and natural sound. Representative medical devices of this type are the Vibroacoustic Bridge Hearing Implant System from Medi Austria and the MET Hearing Implant System from Cochlear Australia. Middle ear implantable hearing devices can generally be considered for implantation at the age of about 3 years, but it is very important to select the right patient and the procedure is significantly more delicate and complex than with implantable bone-conduction hearing devices. Clinical experience in Europe and the United States suggests that middle ear implantable hearing devices can bring patients the following results: clear and natural sound, no whistling, canal blockage and sound distortion, no need to reconstruct the external ear canal; as long as the surgical indications are chosen appropriately, patients can obtain satisfactory and stable hearing reconstruction. Conventional external auditory canal and middle ear reconstructive surgery is generally aimed at children with minor microtia and middle ear deformities, such as simple atresia of the external auditory canal or abnormal development of the auditory tuberosity and normal development of the middle ear tympanic chamber. In conclusion, hearing reconstruction for congenital microtia must be based on the specific situation of the child to achieve good results.