Low-frequency (reverse slope) hearing loss

This type of hearing loss mainly affects the volume of low-frequency sounds. So sounds at this pitch may seem quieter than they actually are.

“Impossible,” you say, “a person could never have such good and bad hearing at the same time!”

One of the more rare forms of hearing loss is known as low-frequency hearing loss, often referred to as “reverse-slope” hearing loss. This name is because of how it appears on an audiogram, a standardized chart audiologists and hearing instrument specialists use to measure hearing levels during testing.

How it affects what you hear

Low-frequency hearing loss is defined as a reduced ability to hear low-pitched sounds, such as men’s voices, bass sounds in music and thunder. How well you hear these sounds—or not—depends on the degree of your hearing loss, which can range from mild to profound.

When it comes to speech, this type of hearing loss mostly affects how you perceive the volume of speech—as in, how loud it sounds. It also makes it harder to hear vowel sounds, which are spoken at a lower-pitch than consonant sounds. Unlike high-frequency hearing loss, it’s helpful to have people speak louder, as it will improve your ability to hear lower sounds (assuming you don’t wear hearing aids).

Symptoms of low-frequency (reverse slope) hearing loss

While it might initially seem fairly easy to “get by” when you have some subtle symptoms of low-frequency hearing loss, you will likely begin to miss out on important sounds, which can impact your quality of life.

You may find it easier to understand women and children versus men, especially if they talk loudly. You may struggle to hear on the phone when compared to in-person conversations. Also, car, truck and airplane engines probably don’t make many “rumbling” sounds for you, and music may sound very tinny. You might also seem uncannily good at hearing very high-pitched sounds that other people don’t notice or can’t hear. You may prefer people stand very close when they speak to you. Your own spoken speech probably sounds fairly normal.

• Low-frequency sounds are difficult to understand

You have a hard time hearing low-pitch, deeper sounds (such as a man’s voice)

• Difficulty following conversations

You have difficulty following group conversations – especially when there’s background noise

• Phone conversations are unclear

You may struggle to hear phone conversations, and often ask people to repeat what they’ve just said

Causes of reverse-slope hearing loss

In some cases, this type of hearing loss is genetic or acquired after a childhood illness. But most cases are linked to autoimmune disorders, Hereditary factors,

otosclerosis or Meniere’s disease, which causes hearing loss, dizziness and tinnitus. However, in Meniere’s, the hearing loss may evolve over time, progressing to other types of hearing loss that affect sound across the spectrum of pitches.

While the link is not well-understood, low-frequency hearing loss is a known risk factor for cardiovascular disease.

Low-frequency sensorineural hearing loss

Sensorineural hearing loss can result in low-frequency hearing loss, meaning that it’s caused by damage to the hair cells in a specific region of the cochlea (in the inner ear).

Since it’s the hair cells’ role to make sure that sound travels from the outer ear to the brain, damage to these cells can seriously impact your ability to hear properly.

How is it diagnosed?

Unfortunately, because this type of hearing loss is rare, it’s sometimes misdiagnosed or undiagnosed for years, if not decades. Standard hearing tests are usually set up (or calibrated, in scientific terms) to detect other types of hearing loss.

With correct and rigorous testing, though, an audiogram will show a “reverse-slope” that slopes from low to high, a pattern that indicates the loss of low-pitched sounds. This is opposed to the far more common high-frequency hearing loss, which slopes from high to low on an audiogram.

Treatments for reverse-slope hearing loss

Hearing aids can help amplify lower sounds without over-amplifying higher-pitched sounds. However, because of the rarity and complexity of this type of hearing loss, it can take a little (or a lot) of trial and error to find the right amplification.

One issue you might deal with, for example, is a hearing loss phenomenon known as recruitment. You’ll want a patient and experienced audiologist to help you sort out the best treatment for you.

If you have Meniere’s, it’s important to follow your doctor’s recommendations to preserve what hearing you have.

Some people might feel that low-frequency hearing loss doesn’t have as much of an impact on their daily lives as high-frequency hearing loss might have. But the effects can take their toll on daily activities as the sufferer starts to experience fewer and fewer of the sounds around them.

It’s important to get professional advice and support whenever any symptoms of hearing loss occur.

Tip from an audiologist

Since low-frequency hearing loss is less common than high-frequency hearing loss, it is a good idea to be aware of the signs and symptoms. This way you can identify if you might have low-frequency hearing loss – and get professional advice more quickly.

It can be difficult to identify low-frequency hearing loss yourself, since many of the signs are similar to other forms of hearing loss. Just knowing what the signs of hearing loss are and when to take a test are great ways for staying on top of your hearing health.

How to get help

If you or a loved one suspect you have reverse-slope hearing loss, don’t hesitate to visit a hearing aid center near you. If you have reverse-slope hearing loss and would like to share your experience to help others, please leave a comment below.

References

1.  Niskar AS, Kieszak SM, Holmes A, Esteban E, Rubin C, Brody DJ. Prevalence of Hearing Loss Among Children 6 to 19 Years of Age: The Third National Health and Nutrition Examination Survey. JAMA. 1998;279(14):1071–1075. doi:10.1001/jama.279.14.1071
2.  Parving A, Sakihara Y, Christensen B. Inherited sensorineural low-frequency hearing impairment: some aspects of phenotype and epidemiology. Audiology. 2000 Jan-Feb;39(1):50-60. doi: 10.3109/00206090009073054. PMID: 10749071.
3. MarkeTrak 10, Marketing Research, Inc.
4. Kuk, Francis, et. al. 2003. Changing with the Times: Managing 5. Low-Frequency Hearing Loss. Hearing Review, November 2003.
5. The Bizarre World of Extreme Reverse-Slope Hearing Loss (or Low Frequency) Hearing Loss, Neil Bauman, Ph.D., 2019