Hearing loss affects more than 48 million Americans. Most have trouble hearing the chirping of birds and the voices of women and children. But for a small group, their hearing loss affects their ability to hear low-frequency sounds.
How You Hear Sounds
When you hear your doorbell ring, there is a complex process that happens in order for your brain to know your delivery from Black Tap has arrived.
The soundwave from the doorbell enters your ear and is funneled through the ear canal where it hits the eardrum. This creates a vibration, which is passed through the small bones in the middle ear until it reaches the cochlea. Within the cochlea, located in your inner ear, there are delicate hair cells. These cells are responsible for converting the vibration into an electrical impulse. This impulse is sent via the auditory nerve to the brain where it is processed as sound.
Types of hearing loss are classified by the point in the hearing process that the problem originates. Conductive hearing loss occurs when there is a problem in the outer or middle ear. Sensorineural hearing loss occurs when there is an issue in the inner ear or auditory nerve.
How Sounds Are Measured
Sounds move through the air in waves. Each soundwave has a specific frequency and amplitude.
A soundwave’s frequency, also called its pitch, is a measurement of the number of times per second it repeats itself. Hertz (Hz) is the unit of measure used for frequency. A human with normal hearing can hear sounds between 20 Hz to 20,000 Hz. Someone with low-frequency hearing loss would have trouble hearing sounds measuring 2,000 Hz or lower. These sounds may include:
- The beat of a drum.
- A clap of thunder.
- An airplane overhead.
Amplitude is the measurement of the strength of a soundwave. This is known as the sound’s loudness or volume. Amplitude is measured in decibels (dB). Anything measuring more than 85 dB can cause permanent damage to the delicate hair cells within your inner ear, leading to sensorineural hearing loss.
The Center for Disease Control and Prevention put together this list of the decibel measurements of common sounds:
- Normal conversation – 60 dB.
- City traffic – 85 dB.
- Motorcycle – 95 dB.
- Sporting events – 100 dB.
- Rock concert – 110 dB.
- Firecrackers – 140 dB.
Low-Frequency Hearing Loss Causes & Treatments
There are a number of causes of low-frequency hearing loss, including problems in the inner or middle ear. The most common causes include:
- Meniere’s disease.
- Wolfram syndrome.
- Ramsay Hunt syndrome.
- Secretory otitis media.
If possible, treating the underlying cause of your low-frequency hearing loss will allow you to regain your hearing. For those who cannot benefit from medication or surgery, hearing aids are often recommended.
To learn more about low-frequency hearing loss or to schedule an appointment with a hearing expert, contact Nevada Ear + Sinus Institute today.