Where’s the one place you should never kiss a baby — or anyone else? The ear, according to a professor of audiology at Hofstra University in Hempstead, N.Y.

An innocent kiss right on the ear opening creates strong suction that tugs on the delicate eardrum, resulting in a recently recognized condition known as “cochlear ear-kiss injury.” Such a kiss can lead not only to permanent hearing loss, but a host of other troubling ear symptoms including ringing, sensitivity to sound, distortion and aural fullness.

Hofstra University’s Dr. Levi Reiter has been studying the phenomenon ever since a woman came to him five years ago with a strange story about going deaf in one ear immediately after her five-year-old kissed her there.

“I thought this lady was a unique case,” says Reiter. After a bit of research, though, he discovered another case of ear-kiss injury reported in the 1950s.

Once the so-called “kiss of deaf” was written up in Newsday, however, Reiter started hearing from people worldwide. He has now identified more than 30 ear-kiss victims (and hopes to hear from more), and is preparing to submit his most recent findings to the International Journal of Audiology and the International Journal of Pediatric Otorhinolaryngology.

Ear-kiss patients exhibit a characteristic pattern of hearing loss, Reiter said, with hearing most diminished in the frequency range of unvoiced consonants, such as “ch” and “sh.”

“There are a lot of cases of unknown unilateral hearing loss in kids, and I am sure that a good portion are from a peck on the ear,” he says.

Babies and small children are particularly vulnerable to hearing damage via kiss, simply because their ear canals are smaller. A baby will cry after such a painful kiss, he says, but “kids cry for a lot of reasons.” Unfortunately, hearing loss usually isn’t identified until years later, during a school screening.

Unilateral hearing loss can be acquired from a blow to the ear, impulse noise (like an exploding firecracker) on one side of the head, or a Q-tip pushed too far.

An ear-kiss is another cause, formerly undiscovered, said Paul Farrell, associate director for audiology practices at the American Speech-Language-Hearing Association. “It is a fascinating phenomenon,” he said. “I would consider it an emerging topic in the field.”

Reiter believes that the intense suction on the eardrum pulls the chain of three tiny bones in the ear. The third bone, the stirrup-shaped stapes, then tugs on the stapedial annular ligament, causing turbulence in the fluid of the cochlea, or inner ear.

Reiter is full of horror stories of ear-kiss injuries resulting from normal everyday activities: a hairdresser sending a client off with a nice hairdo and a smack on the ear; a relative’s air-kiss going astray after a quick turn of the head; a mother seeing her little girl off to school with a loving smooch.

Still, the prevalence of the injury is unknown.

“People are going to doctors who are pooh-poohing this,” says Reiter. “One reason these people wrote to me in the first place was that they were getting nowhere. The doctors were making fun of them. They felt humiliated.”

Joe Fields, an 82-year-old jazz producer from Long Island, received a kiss on the ear from his adult granddaughter a few years ago that left him with a host of hearing problems.

“It felt like if you got hit by a ball on the ear,” he says. “It’s like hearing through a screen of some sort. In the kissy ear, speech is totally muffled.”

Fields, a patient of Reiter’s, now wears hearing aids, but still experiences intermittent sensations of aural fullness as well as a “deep-seated itch.”

“At times, it feels terrible,” he says.

Reiter speculates that an injection of steroids through the eardrum, which is used in cases of sudden idiopathic deafness, could help if administered within days of an ear kiss.

But there is currently no treatment and symptoms don’t tend to resolve. As a result, Reiter — and patients like Joe Fields — preach prevention.

“My granddaughter is a kindergarten teacher and I tell her never kiss any of your little tykes on the ear,” he says.