Dr. Levi Reiter of Hofstra University in Hempstead, N.Y., said a woman came to him five years ago because she had lost hearing immediately after her 5-year-old child kissed her on the ear, MSNBC.com reported.
Reiter said he thought at the time the woman's case was unique but he found a similar case dating back to the 1950s. After a Long Island newspaper reported his findings he heard from more people who said they had the same experience.
Reiter said the intense suction on the eardrum from the kiss pulls the chain of three tiny bones in the ear causing turbulence in the fluid of the cochlea, or inner ear.
He said since there could be many more cases of this type of unilateral hearing loss because babies and children so lose hearing but parents might not connect it to a kiss.
Unilateral hearing loss can be due to a blow to the ear, a loud noise such as an exploding firecracker on one side of the head, or a Q-tip pushed too far, Reiter said.
Reiter said he plans to submit his findings to the International Journal of Audiology and the International Journal of Pediatric Otorhinolaryngology.