Degrees of hearing loss

In simple terms, the severity of your hearing loss is measured in two ways:

• how loud the volume needs to be before you can hear sound adequately, and
• which frequencies are harder for you to hear (such as higher-pitched sounds). 

Volume is measured in decibels (dB) and frequency is measured in Hertz (Hz). The degree of hearing loss you have primarily refers to how loud you need sound to be before you can hear it. As a reference point, the sound of whispering is about 30 dB while a motorcycle clocks in around 95 dB:

The degrees of hearing loss

• Mild hearing loss: If one-on-one conversations are fine but you’re having difficulty understanding some words when there’s a lot of background noise, you may have mild hearing loss. Technically speaking, it’s defined as having hearing loss up to 40 dB in the speech frequencies.
• Moderate hearing loss: At this level, you are asking people to repeat themselves a lot during conversations–in person and on the telephone. People with this degree of hearing loss cannot hear sounds lower than 40-69 dB. Both mild and moderate hearing loss can typically be treated effectively with standard hearing aids.
• Severe hearing loss: If you can’t hear people speaking without the use of a hearing aid or other amplification, or you tend to rely on reading lips to understand the conversation, you may have severe hearing loss. People with this degree of hearing loss cannot hear sound lower than 70-94 dB.
• Profound hearing loss: If you have profound hearing loss, you can only hear extremely loud conversation or sound–and even then it’s difficult to understand without a hearing aid or cochlear implant. You may prefer using sign language to communicate. People with this degree of hearing loss cannot hear sound lower than 95 dB.

How sound is measured

As mentioned, the loudness of sound is primarily measured in units called decibels (dB). Here are decibel levels for some common sounds:

• Breathing: 10 dB
• Normal conversation: 40-60 dB
• Lawnmower: 90 dB
• Rock concert: 120 dB
• Gunshot: 140 dB

Prolonged exposure to sounds louder than 85 dB can cause damage to your hearing; sound at 120 dB is uncomfortable and 140 dB is the threshold of pain. This is known as noise-induced hearing loss. 

Measuring pitch

The other way sound is measured is frequency, or pitch. It's measured in Hertz (Hz). When hearing ability is tested, a range of 250 Hz to 8000 Hz is measured because it encompasses the speech frequencies, the most important range for communication. People can have varying patterns of hearing loss in different frequencies, but the more common ones are:

• low-frequency hearing loss
• mid-range hearing loss
• high-frequency hearing loss (most common)

If you have high-frequency hearing loss, for example, you struggle to hear high-pitched sounds such as birdsong and children's voices.

Detecting hearing loss

The hearing healthcare professional will administer a series of hearing tests. The outcome of the evaluation is known as an audiogram, a graph of the softest sounds you heard during your test. Here’s an example of an audiogram of someone with mild-to-moderately-severe high-frequency hearing loss. This person could easily hear thunder but not the sound of birds.

As you can see, hearing thresholds in each ear are not always the same:

Hearing levels in both ears should be similar

Generally, the degree of hearing loss is typically similar in both ears. When there is hearing loss present in both ears, but one ear is significantly worse, it's known as asymmetrical hearing loss and it sometimes has a medical cause.

Treatment is based on the degree of hearing loss

Based on the outcome and the lifestyle information you provide, your hearing healthcare professional will be able to recommend a course of treatment, which may include the purchase of hearing aids and enrollment in auditory therapy classes. Keep in mind, untreated hearing loss puts you at risk for developing a host of other health-related problems, including depression, dementia and Alzheimer’s disease.

The good news? Increasingly, research is showing that hearing aids can do far more than just help you hear. They may also make you healthier. Learn more about the health benefits of hearing aids.

Need a hearing test? Search our consumer-reviewed directory of hearing care providers near you.