"When someone is blind or in a wheelchair, people open doors. They offer their help. But when you can't hear, people get mad at you," a male friend in his 70s remarked recently.

My cousin agrees.

During a phone conversation, she suggested I write a column about the rudeness directed at folks who have an invisible disability: hearing loss.

She has firsthand experience. She has seen the impatience and eye rolling when she asks someone to repeat a message.

She was the target of mockery by a coworker in her workplace.

Even in a doctor's office, of all places, she endured hostile looks and loud sighs when she needed to have an aide's questions repeated during the preliminary intake process.

"People get frustrated with you," my cousin said.

Just because a person looks perfectly healthy and fit, as my attractive cousin does, he or she could still have an invisible medical problem.

As many of us know, not all disabilities are readily apparent, and that can cause a problem.

An older female friend, who suffers from a heart ailment and cannot walk more than a few yards before stopping to rest, reports insensitive and angry comments tossed her way, especially when she parks (legally) in a "handicapped" space.

We've heard other people refer to her as lazy, because she is unable to keep up.

Like hearing loss, a heart condition cannot be detected by looking at a person. But that doesn't mean the disability is imaginary.

Rudeness abounds.

In an example I will remember for the rest of my life, I once heard an obnoxious woman tell a total stranger he was "lousy" at dancing the polka.

Actually he was quite good, considering he had lost a leg in Vietnam and was wearing a prosthesis, hidden by his trousers.

And he certainly was a better dancer than that woman, who never got up from her chair!

Allergy and asthma sufferers often incur ridicule and are not taken seriously.

One friend, who negatively reacts to all kinds of scents, says she sometimes gets snide comments when she requests that friends and nearby coworkers refrain from wearing strong fragrances.

She also reacts to cigarette smoke and tries to avoid it, raising the ire of die-hard smokers who call her a "sissy."

A woman who has several cats in her house dismisses a friend's explanation of why he can visit her only outdoors on her patio. He is allergic to cats, which trigger serious asthma attacks when he is near them.

The cat owner has called him, to his face, "a baby." Any attempts to educate her about asthma fall on deaf ears.

Speaking of deaf ears, critics of invisible disabilities such hearing loss might better focus on their own deficiencies in communicating with hearing-impaired individuals.

If a listener cannot see the person addressing him and can't read the speaker's lips, it is no surprise he won't respond.

Talking louder to a person with hearing loss will not increase his understanding. In fact, shouting distorts sound, and the exaggerated mouth movements may actually confuse the listener as he tries to read lips.

To succeed in communicating with a hearing-impaired person, the speaker should remove any obstacles from his mouth, such as food or gum, before facing and addressing the listener.

It is also important to get the listener's attention before starting to speak, and to make sure the environment is appropriate.

Avoid noisy background sounds such as a radio or television or other competing voices, if possible.

Just as we cannot judge a book by its cover, we also can't judge someone's health by outward appearance.

Maybe he really does need that special parking space; maybe she really will stop breathing if she eats a peanut.

So why not give a person the benefit of the doubt?

People who can't, or won't, truly are the ones with a serious disability.