What Is Low Frequency Hearing Loss?
A low frequency hearing loss is a sensorineural hearing loss (hearing loss caused by damaged inner ear hair cells). People with low frequency hearing loss cannot hear sounds in frequencies 2000 Hz and below. A low frequency hearing loss is also known as a "reverse slope audiogram" because someone with low frequency hearing loss may still hear sounds in the higher frequencies. Due to that, people with low frequency hearing loss often can still understand human speech well.
What Causes Low Frequency Hearing Loss?
The Kresge Hearing Research Institute reported that a mutation in the WFS1 gene (the Wolfram Syndrome gene) can cause low frequency sensorineural hearing loss. The mutation is called Wolfram Syndrome 1. Other causes of low frequency hearing loss include Mondini dysplasia, sudden hearing loss, and Meniere's disease.
How Common is Low Frequency Hearing Loss?
The Third National Health and Nutrition Examination Survey (1988 to 1994) of 6,166 children ages 6 to 19 who received audiometric exams found that 14.9% of children had low frequency or high frequency hearing loss of at least 16 decibels, while just 7.1% had low frequency hearing loss of at least 16 decibels.
However, a low frequency hearing loss is not easy to identify because it tends to not have any symptoms. In fact, lower frequency sounds do not have as much information as sounds in the higher frequencies. Plus, people with hearing in the middle and high frequencies can use what they hear in those frequencies to make up for what they do not hear in the lower frequencies, thereby "masking" the hearing loss. One of the few clues to a low frequency hearing loss is that the person has difficulty hearing in groups or in a noisy place.
How Do You Treat Low Frequency Hearing Loss?
Hearing aids, particularly advanced multichannel hearing aids, can help with a low frequency hearing loss. However, care has to be taken with the use of hearing aids, as overamplification is a risk. If low frequency sounds are amplified, it can make it more difficult to hear higher frequency sounds, and it can also make it harder to tolerate loud sounds.
More about low frequency hearing loss:
Kuk, Francis, PhD, DeniseKeenan, MA, and Carl Ludvigsen, MS. Changing with the Times: Managing Low-Frequency Hearing Loss. Hearing Review November 2003. http://www.hearingreview.com/issues/articles/2003-11_04.asp. Accessed March 2011.
Lesperance MM. WFS1 Gene Mutation and Polymorphism Database. Low-Frequency Hearing Loss. Kresge Hearing Research Institute. Human Genetics Laboratory. http://www.khri.med.umich.edu/research/lesperance_lab/low_freq.php. Accessed March 2011.
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 Apr 8;279(14):1071-5. http://jama.ama-assn.org/content/279/14/1071.long Accessed March 2011.