Since my last article four years ago on the topic of frequency shifting, technology has progressed.

Modern hearing aids can capture sounds at their original frequencies and quickly rebroadcast them at lower frequencies — a process called frequency shifting. This helps patients with severe high-frequency hearing loss understand softer consonants and voices, even if louder volume alone isn’t enough. For example, a husband may better hear his wife’s higher-pitched voice when it is shifted to a range where his hearing is less impaired, though her voice will sound slightly different.

“Frequency Shifting (lowering) is a useful feature that many hearing aid users aren’t aware of,” says Dr. Steven Sederholm, an audiologist in Boynton Beach, Fla. himself, with severe hearing loss.

Also known as frequency compression or sound recovery, this technology helps with speech in noisy environments — a common issue for hearing aid wearers. Many who would benefit from it don’t have it enabled. (Audiology Online)

Many people with hearing loss do not use hearing aids, even though they can help. Only 16 percent of adults aged 20-69 who could benefit have tried them (WebMD). There are several types of hearing aids; if your hearing loss affects high or low frequencies, frequency-shifting hearing aids may help.

In review, modern hearing aids offer a “frequency shifting” setting, also known as “frequency transposition” or “frequency movement,” which lowers the pitch of higher frequency harmonics. This helps people with hearing loss in damaged frequency regions, but doesn’t always improve their perception of certain notes, especially those affected by “cochlear dead regions.”

While frequency compression works well for speech most of the time, it is less effective for music, which consists entirely of notes and harmonics. These need to occur at exact frequencies, not sharp and not flat. Using frequency compression will alter the frequency of a range of harmonics and this altered harmonic structure would be, at best flat, and at worst highly dissonant.

In contrast for speech, those sounds that are frequency compressed are the “s” and “sh” sounds; sounds that are broad band noise or sibilant, and not at “exact” frequencies.

I personally don’t use the frequency shifting function in my own hearing aids as it gives my wife a soft lisp at the end of her words.

Frequency shifting software is not a cure all magic wand. It still takes trial and error in programming adjustments by a competent hearing care professional.

If you have the symptoms of hearing loss, schedule an appointment with a professional soon.

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Jeff Bayliff is owner of Hear the Birds Hearing Aid Center in Lock Haven.