Your mother was right. Turning down highly amplified music is sound advice. But don't take our word for it.

A Roanoke Valley speech and hearing center has come out with a $49.95 test device to gauge the risk of hearing damage from popular personal music players and other sources. It's of interest to music lovers, among other groups, and is raising eyebrows with its tendency to blink brightly at the first hint of noise.

"Higher than expected," said Ian Shaw, 37, of Roanoke, who allowed an impromptu test to be performed on the ear pieces that filled his head with music from the New Wave band New Order. The newly released testing device, called the Ear3 Sonic Threat Indicator, warned he was in high danger of hearing loss even though Shaw didn't consider the volume dangerous.

Why the disconnect? What many people would consider low to medium volume for music is at the edge of the danger zone recognized by the Ear3. What sounds loud is dangerous, as indicated by the Ear3's flashing red warning signal.

Momentary exposure to loud sounds isn't necessarily going to cost people with healthy ears their hearing. But sustained exposure can bend or break off the tiny hairs that send nerve signals from the inner ear to the brain. For example, a minute's use of a hair dryer isn't going to make anyone deaf, but more than 15 minutes continuous usage could do damage because the running appliance produces about 100 decibels of sound.

Research psychologist Ronald Webster, psychoacoustics expert Duncan MacAllister and product engineer Robert Capper of the not-for-profit Hollins Communications Research Institute in Roanoke County developed the Ear3, packing years of research in a 4-ounce box that fits in the hand. Developed for less than $1,000, it couples sound meter technology, a logic circuit and a lighted indicator that gives four signals: safe, danger, high danger and immediate danger. The sound intake hole is ideally shaped for testing ear buds, miniature speakers that can deliver hours of head-filling music when worn in the outer ear. It's for sale only at www.ear3.info. (There's no affiliation with Hollins University).

As anyone who tinkers with an Ear3 quickly discovers, the volumes the device deems unsafe are within a range that some people can tolerate -- and might even enjoy.

Jason Clary, 17, has a reputation at Community School in Roanoke as the student who probably plays his MP3 the loudest. He listens to black metal music from Scandinavia, known for abrasive, dark sounds and lyrics that are often screamed. His friends have no choice but to listen, too.

"You could hear the music 15, 20 feet away," said student Cap Pritch, 15.

Clary, who has been directed to cut back listening to lunch hour only by school officials, said he believes his hearing has been affected.

"I don't hear as well as I used to," Clary said. "It don't know if it's the iPod or not."

Webster told The Associated Press that young, healthy ears can recover from limited exposure to loud noise, but "repeated insults lead to hearing loss."

But Webster said people can lose half of their hearing range without noticing it. The loss may be treatable only with hearing aids. That's a solution that more middle-aged people appear to be turning to. Hearing centers that for years mostly treated patients 60 and older are reporting an influx of people in their 40s and 50s, Webster said.

"We're so concerned about eating properly, exercising and getting physical checkups, and we're idiots about our ears," Webster said. That may be changing. He's gotten about 50 orders for the Ear3 since it went on sale Dec. 1.

The National Institute on Deafness and Other Communication Disorders estimates that 32.5 million Americans have some degree of hearing loss, with about 22 million having suffered permanent damage from loud noise.

Manufacturers have responded to the threat posed by their devices -- sometimes only after government health and safety officials had registered their concern. In addition to product warning labels that make it clear hearing damage can occur at peak volumes, the latest version of the iPod software allows a user to restrict the volume knob from exceeding safe volume limits. Apple Computer, in 2002, had pulled its iPods from stores in France because the maximum volume exceeded the government's limit of 100 decibels.

Sherry Landis, hearing aid specialist at Gill Memorial Clinic in Roanoke, said she believes the Ear3 would be more effective if it came with a timer. That's because time goes hand in hand with volume to create the risk for hearing damage.

"You can be exposed to 85 decibels of music for eight hours before it will start damaging your hearing," Landis said. However, music at 120 decibels becomes unsafe after a few minutes, she said.

Raymond Hull, a professor of communication sciences and disorders at Wichita State University, called the Ear3 well-suited to testing ear buds. However, he said he doubted it would work as well in a spot such as a nightclub where the volume goes up and down.

Ear3 is "an interesting concept and should be usable by the general public," Hull said.

The question this all leads to is, when the machine signals danger, what does a user do? Hull said he's proved through research that earplugs handed out at a Motley Crue rock concert brought down noise exposure by 30 decibels into a safer range. The Ear3 team has thought of that and ships six pairs with each purchase.

With a personal stereo system, of course, turning the volume down is always an option.