How is Hearing Loss Measured?

Hearing Health, Lifestyle
April 2, 2024
Ross Cushing

Hearing loss is a prevalent condition affecting millions worldwide, with various contributing factors such as noise exposure and aging. Despite how common hearing loss is, most people don’t understand much about how hearing loss is actually measured. This blog post aims to explain the process by which professionals like the audiologists at Live Better Hearing + Balance evaluate your hearing, underscore the importance of routine hearing assessments, and highlight how these evaluations inform treatment decisions with your hearing health care provider.

Understanding Hearing and Its Measurement

Sound, a fundamental element of our environment, is essentially a series of vibrations traveling through the air, capable of being picked up by the human ear. These vibrations, or sound waves, are created when an object vibrates, causing the air around it to move. This movement of air molecules reaches our ears and is transformed into electrical signals that our brain interprets as sound.

The two main characteristics of sound that are crucial in the context of hearing assessments are amplitude and frequency. Amplitude refers to the strength or intensity of the sound wave, which determines how loud the sound is perceived. This intensity is measured in decibels (dB), a logarithmic unit that quantifies the relative loudness of a sound compared to a reference point, usually the threshold of human hearing. For example, a whisper is around 30 dB, normal conversation is approximately 60 dB, and a rock concert can reach levels of 120 dB or more.

Frequency, on the other hand, refers to the rate at which the sound wave vibrates per second and is measured in hertz (Hz). It determines the pitch of the sound, whether it's high like a bird chirping or low like a drumbeat. Human hearing typically ranges from 20 Hz to 20,000 Hz, with the ability to discern pitch diminishing with age, especially at higher frequencies.

The Hearing Test Process

When you visit an audiologist for a hearing test, you're stepping into a carefully controlled environment designed to accurately assess your hearing capabilities. The process is nuanced, involving a series of tests that together provide a detailed picture of your auditory health.

Pure Tone Audiometry

At the heart of the hearing test is pure tone audiometry, a method used to identify the softest sounds you can hear at different frequencies. In a soundproof booth, the audiologist uses an audiometer to produce sounds at various pitches (frequencies) and loudness (intensities). You'll typically wear headphones or earphones, and each ear will be tested separately to gauge its specific response.

The test begins with the presentation of a series of beeps or tones at different pitches. You'll be asked to respond—often by pressing a button or raising your hand—every time you hear a sound, no matter how faint it is. The objective is to find the threshold, the lowest decibel level at which you can reliably detect a sound at each frequency. This threshold helps to determine not just the presence of hearing loss but also its degree and nature—whether it's more pronounced at higher or lower frequencies, for instance.

Speech Discrimination Tests

Understanding speech is a complex task that goes beyond simply detecting sounds. That's where speech discrimination tests come in. These tests evaluate your ability to distinguish and understand speech at comfortable loudness levels, providing insights into how hearing loss impacts your communication abilities.

During a speech discrimination test, the audiologist will present a series of words or sentences at a volume that's comfortable for you and ask you to repeat them. This can help assess your clarity of hearing and your ability to distinguish between similar-sounding words. It's a crucial aspect of the test, as difficulties in speech understanding can significantly affect daily communication, even if your ability to detect pure tones is relatively intact.

Additional Assessments

Besides pure tone audiometry and speech discrimination tests, audiologists often conduct a range of additional assessments and objective testing to gain comprehensive insights into your hearing:

1. Tympanometry: This test evaluates the middle ear's function, specifically the mobility of the eardrum and the conduction bones. By changing the air pressure in the ear canal, the audiologist can determine how well the eardrum moves and whether there are any issues like fluid in the middle ear or perforations in the eardrum.

2. Acoustic Reflex Testing: Measuring the reflexive contraction of the middle ear muscles in response to loud sounds can provide information about the auditory pathway, from the ear to the brainstem.

3. Otoacoustic Emissions (OAEs): This test measures sounds that the inner ear (cochlea) produces in response to auditory stimuli. Absence or significant reduction of these emissions can indicate cochlear dysfunction.

By synthesizing the results from these various tests, an audiologist can craft a detailed profile of your hearing health, pinpointing areas of strength and weakness. This comprehensive understanding is vital for devising effective treatment plans, whether they involve hearing aids, therapeutic strategies, or further medical evaluation.

Hearing Assessments for Infants, Toddlers and Young Children

Early identification and management of hearing loss in infants and children are imperative for their language acquisition, educational achievement, and social integration. Audiological assessments for this age group are tailored to meet their developmental and cognitive abilities, ensuring accurate and effective evaluations.

Hearing Tests for Newborns and Infants

Most hospitals and birthing centers implement newborn hearing screenings before discharge. These screenings are crucial as they lay the foundation for early intervention, which is vital if a hearing loss is detected. Two primary non-invasive tests, Otoacoustic Emissions (OAE) Testing and Auditory Brainstem Response (ABR) Testing, are used for newborns.

Hearing Tests for Children

As children grow, the strategies for assessing their hearing evolve to align with their developmental stages. Audiologists will utilize Visual Reinforcement Audiometry (VRA), capitalizes on a child's natural head-turning response to sound; Conditioned Play Audiometry (CPA), which is deal for preschool-aged children and transforms the hearing test into a game; and Speech Detection and Recognition Testing, which is used to assess the softest level at which a child can detect and understand speech.

Nearly all of our hearing centers welcome pediatric patients, and our Frederick, MD hearing clinic is proud to work closely with Frederick Health Hospital that refers newborn hearing screening patients to our providers.

The Audiogram and Types of Hearing Loss

An audiogram is essentially a chart that audiologists use to visually represent your hearing ability. It's a vital tool that helps both you and your healthcare provider understand more about your hearing loss and how it might be affecting your daily life.

Understanding the Audiogram

Types of Hearing Loss

Understanding your audiogram and the type of hearing loss you have is crucial for determining the most effective treatment plan. Whether it's medical intervention, hearing aids, or other hearing assistive devices, the goal is to improve your hearing ability and, consequently, your quality of life. If you have concerns about your hearing, getting tested is a critical first step.

Degrees of Hearing Loss

The extent of hearing loss is not uniform; it varies from person to person and is classified into several degrees based on the intensity of sounds that an individual can hear. Understanding these degrees helps in creating effective treatment plans and strategies for communication.

Mild Hearing Loss (21 - 40 dB): Individuals with mild hearing loss might find it challenging to follow conversations, especially in noisy environments. They may frequently ask others to speak more slowly or clearly and may have difficulty hearing softer sounds like birds chirping or distant conversations. Such individuals typically benefit from hearing aids, which amplify the sounds to assist in clearer hearing.

Moderate Hearing Loss (41 - 55 dB): At this level, following a conversation without the use of a hearing aid becomes more challenging. People with moderate hearing loss may not hear doorbells, conventional phone ringtones, or even a conversation at a normal volume. Hearing aids are often recommended to amplify sounds and improve the ability to understand speech.

Moderately Severe Hearing Loss (56 - 70 dB): Individuals with this degree of hearing loss may not hear sounds that are less than 56 dB. They might find it difficult to understand even loud speech without the use of hearing aids or other assistive listening devices. The clarity of speech is often significantly impacted, making everyday communication without assistance quite challenging.

Severe Hearing Loss (71 - 90 dB): Severe hearing loss implies that the individual might not be able to hear sounds below 71 dB. Conversations have to be extremely loud to be heard, and understanding speech without a hearing aid or cochlear implant can be very difficult. People with severe hearing loss rely heavily on visual cues or sign language for communication.

Profound Hearing Loss (91 dB or greater): This is the most significant degree of hearing loss where individuals may not hear sounds below 91 dB, which includes most ambient noises and normal conversation. People with profound hearing loss benefit from cochlear implants, which can provide a sense of sound and assist in understanding speech, or they may rely on sign language as their primary mode of communication.

The categorization into these levels is not just for clinical assessment but is essential for determining the most suitable intervention. While hearing aids might be beneficial for mild to severe hearing loss, cochlear implants could be considered for profound hearing loss. In all cases, the goal is to enhance hearing as much as possible, allowing individuals to communicate effectively and improve their quality of life. Understanding the degree of hearing loss is a critical step in this journey, guiding professionals and patients alike in choosing the best path forward.

Treatment and Management of Hearing Loss

Treatment options vary based on the hearing loss type and degree, ranging from amplification devices like hearing aids to cochlear implants for more severe cases. At Live Better Hearing + Balance, treatment plans are meticulously crafted, considering the individual's specific audiometric results, lifestyle and employment needs, and personal preferences to provide the most effective and accommodating solutions.

The measurement of hearing loss is a critical process that provides a foundation for understanding an individual's hearing health and determining the best course of action to address any impairments. 

If you've noticed changes in your hearing or wish to have a routine evaluation, Live Better Hearing + Balance is here to assist you. Through comprehensive hearing assessments and personalized care, our team is committed to helping patients navigate their hearing loss, offering solutions that enhance their quality of life.

Contact us at (888) 432-7505, or find a location near you, to schedule a detailed hearing assessment with our experienced audiologists. Let us partner with you on your journey to improved hearing and overall well-being.

Chief Executive Officer
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Written by Ross Cushing

Ross Cushing, Au.D., is the Chief Executive Officer at Live Better Hearing + Balance. Dr. Cushing has been a clinical audiologist for nearly 20 years and chief leader of Live Better Hearing + Balance since 2007, where he believes that it is only through a combination of kindness and competency that we can achieve success with our practice and our patients.

Chief Learning & Development Officer and Audiologist
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Reviewed by Dr. Jenifer Cushing

Dr. Jenifer Cushing is the Chief Learning & Development Officer of Live Better Hearing + Balance and an audiologist in the Frederick, MD clinic. Dr. Cushing earned a Bachelor of Arts in Hearing & Speech Science from the University of Maryland, College Park and a Doctorate in Clinical Audiology from the University at Buffalo.

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