The cause of hirsutism of the external auditory canal is recognized to be inherited from the Y chromosome and is transmitted only to males. Hirsutism of the external auditory canal is also known as human Indian hairy ear hirsutism of the external auricle.The causative genes for this type of genetic disorder are located on the Y chromosome, which is a sex chromosome exclusive to males.There are no genes associated with hirsutism of the external auditory canal on the X chromosome. Therefore, these genes only follow males and are passed from father to son and from son to grandson for generations. As a result, it only occurs in men with a family history of the condition. Although the incidence of this disorder is still relatively low, it is more disruptive to appearance. At birth, boys are born with brownish hairs in the external auditory canal, which turn black after the age of six, and then become black during puberty, with significant growth. In severe cases of hirsutism, the hairs can reach 4-5 cm. There may be other causes of hirsutism of the external auditory canal, and it is recommended to actively seek medical treatment and adopt reasonable treatment methods.