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July 8, 2004

New sound wave

From: Biloxi Sun Herald, MS - Jul 8, 2004

Digital hearing aids overtake analog devices


Get out of the way analog, here comes digital. The long arm of advancing digital technology is taking over the hearing aid industry and making the analog processor as obsolete as an eight-track tape.

According to a nationwide network of licensed audiologists and hearing consultants, Web sites and the latest hearing association statistics, seven out of 10 hearing aids sold in the U.S. are digital.

David Elder of Miracle Ear in Gulfport says their whole line has switched completely to digital.

Karen Slater, a doctor of audiology in Gulfport, agrees.

"Most people are going to digital," she said. "I did have many of my manufacturers say they were going to phase out the analog over the next three years. Analogs aren't even on the order form. You have to write it in."

Carl Schulz, hearing specialist at Schulz's Hearing Lab in Gulfport, manufactures his own hearing aids, and he says there's another reason for the change to digital: "The problem is that they're finding it hard to get electrical engineers to design the analog circuits and keep the programming up to date."

According to "Hearing Aids: A User's Guide," analog aids work by receiving an acoustical signal (any exterior sound), changing it to electrical voltage, processing that according to a circuit design and then changing it back to an acoustical signal.

In digital hearing aids, the acoustical signal is sampled (recorded) many times a second, turned into mathematical 1s and 0s that are manipulated according to programming and then turned back into an acoustic sound for the wearer to hear.

Schulz says it's the faster processor that really makes the difference.

"No hearing aid is 100 percent digital," said Schulz. "The microphone is an analog input and the receiver is analog. It's only the processor that's changed. The analog hearing aid processors just don't work as fast."

Slater says, "It started off with analog, and then they changed to analog/digital/programmable (which) were able to hook up to a computer (where) you might have an option to change a few things. Now they're digital. It's all on the computer, and the manipulation that we are able to do... is almost astronomical."

Digital hearing aids have faster processors, the sound quality is better, they have better noise vs. speech recognition, programmable scenarios, and they are programmed to the tones of the wearers' specific hearing loss.

The digital hearing aid has been compared to having a graphic equalizer in your ear.

"In an analog hearing aid," Slater says, "the only thing you could really change was the treble and bass. Now we have all the in-betweens." He compares it to the progression from eight tracks (music recordings), "Then they went to cassettes, and everybody thought the sound quality was so much better. Now we have CDs and nobody wants the eight track or cassettes."

Schulz likes the noise vs. speech capabilities of the digital hearing aid.

"In the digital, the faster processor is better and there's so much more you can do. It has the ability to recognize noise vs. speech and reduce the noise. Patients say the sound is much clearer. No hearing aid will completely eliminate noise, (and) nothing is like normal hearing, but we can get pretty close."

That said, Schulz warns that having a smaller hearing aid doesn't necessarily mean you're getting a better hearing aid.

"You're just paying for smaller, miniaturized electronics," he said.

Not everyone is thrilled with digital. Some people who have had powerful analog hearing aids have complained about switching to digital, Slater said.

"The old analog hearing aid had so much power behind it that they could really feel it was on, and they could really hear the sounds. Some complain that when they go to digital, everything is so quiet."

Another difference is in the cost, which is greater for digital than analog. Digital prices have come down, Slater said. They vary by distributor and the technological choices wearers and their doctors can require, but they can range from about $700 to about $2,000 per hearing aid.

Some dispensers provide their own financing. In Mississippi, the Department of Rehabilitation Services provides financial help if you have a loss of 40 decibels or more in both your ears and are employed or are in the process of looking for employment and need the hearing aids for your job. Funds are limited so help is first come, first served.

Analog was good, but Slater said she is really happy that digital technology has made more choices available to her patients. It has really helped her with what she calls her "nightmare" patients with only high-frequency hearing loss. You could just never get it right for them, she said.

"They would want a completely in-the-canal hearing aid, and they would say they heard better without the hearing aids," Slater said. "Last summer GN Resound came out with a mini-behind-the-ear hearing aid that has a very small tube that goes into the ear canal. It is (exclusively) for people with high frequency loss. This type of hearing aid amplifies only the 1,000-6,000 frequency loss," Slater said. "It's just wonderful now to (treat) that type of hearing loss... Thanks to the new digital technology."
Nancy Bosarge is a freelance community news correspondent. Reach her at

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