Hearing loss affects millions of people worldwide and can occur at any age, from infants to seniors. But not all hearing loss is the same. Where the problem occurs within the ear, how severe it is, and how it developed all influence how it should be treated. Understanding the different types and degrees of hearing loss is the first step toward finding the right solution and improving your quality of life.
How We Measure Hearing
Your hearing ability is measured in decibels (dB), with 15-20 dB representing the softest whisper and 120 dB comparable to a jet engine. The softest sounds you can hear are called thresholds, with normal adult hearing ranging from 0-25 dB across tested frequencies. Hearing loss can range from mild to profound and may affect different pitches or frequencies differently, which is why two people with “hearing loss” can have very different experiences.
During a comprehensive hearing evaluation, our audiologists conduct both tone and speech testing to determine your specific type and degree of hearing loss. These tests help create a complete picture of how hearing loss affects your daily communication.
Degrees of Hearing Loss
Hearing loss is classified by how loud a sound needs to be before you can hear it:
- Mild (26-40 dB): Soft speech and background conversation are hard to follow, especially in noisy settings.
- Moderate (41-55 dB): Normal conversational speech becomes difficult without amplification.
- Moderately severe (56-70 dB): Most speech is missed unless the speaker raises their voice.
- Severe (71-90 dB): Only loud sounds are heard; conversation is very difficult without hearing aids.
- Profound (91+ dB): Very little sound is perceived, even at high volume.
Your degree of hearing loss is one factor in determining the most appropriate treatment. The other is the type.
The Three Main Types of Hearing Loss
Conductive Hearing Loss
Conductive hearing loss occurs when sound cannot properly travel through the outer or middle ear to reach the inner ear. The problem may involve the ear canal, eardrum, or middle ear structures, while the inner ear and auditory nerve remain unaffected.
Common causes include:
- Ear infections or fluid in the middle ear
- Earwax blockage
- Deterioration or stiffening of the middle ear bones (otosclerosis)
- Perforated eardrum
- Structural abnormalities of the outer or middle ear
People with conductive hearing loss often describe sounds as muffled or too quiet, and may notice their own voice sounds louder than usual. Depending on the cause, this type of hearing loss may be temporary and treatable with medical intervention, such as removing a blockage or treating an infection. In permanent cases, prescription hearing aids are highly effective, because the inner ear is still able to process sound clearly once it is made loud enough.
Sensorineural Hearing Loss
The most common type of hearing loss, sensorineural hearing loss results from damage to the inner ear’s hair cells or the auditory nerve. This damage prevents sound from being properly transmitted to the brain. Those affected may experience muffled speech, ringing in the ears (tinnitus), or difficulty hearing in noisy environments, even when sound seems loud enough.
Common causes include:
- Age-related changes (presbycusis)
- Prolonged or sudden exposure to loud noise
- Genetic factors
- Certain infections and illnesses
- Ototoxic medications (drugs that can damage the inner ear)
- Head trauma
Because the inner ear’s hair cells do not regenerate, sensorineural hearing loss is typically permanent and may progress over time. However, it responds very well to treatment. Prescription hearing aids programmed to your specific hearing profile amplify the frequencies you’re missing and improve clarity, helping you follow conversation more easily and with less effort.
Mixed Hearing Loss
Mixed hearing loss combines both conductive and sensorineural components, meaning problems exist in both the outer or middle ear and the inner ear. For example, someone with age-related hearing loss may also develop a middle ear infection or earwax buildup, compounding their difficulty.
Treatment typically addresses each component separately: medical management for the conductive portion, and prescription hearing aids to address the underlying sensorineural loss. Once the conductive issue is resolved, hearing may improve, but ongoing amplification is usually still needed.
Other Ways Hearing Loss Is Described
Beyond the three main types, you may hear your audiologist use the following terms:
- Unilateral vs. bilateral: Hearing loss in one ear versus both ears.
- Symmetrical vs. asymmetrical: Whether the degree and pattern of loss is the same in each ear.
- Sudden vs. progressive: Whether hearing loss developed rapidly (which should be evaluated urgently) or gradually over time.
- High-frequency hearing loss: The most common pattern, in which higher-pitched sounds such as consonants, children’s voices, and birdsong are lost first. This often makes speech sound unclear rather than simply quiet.
Finding Out Which Type You Have
The only way to know your type and degree of hearing loss is through a comprehensive hearing evaluation. At Acoustic Audiology, we take the time to explain your results clearly and recommend a treatment plan based on your hearing, your lifestyle, and your goals.
If you’ve noticed changes in your hearing, or someone close to you has, contact us to schedule an evaluation.