Hearing screening test
There are two types of hearing tests: diagnostic and screening. Screening tests, using pure tone audiometry through basic air conduction, are used to quickly determine whether more intensive diagnostics tests are required. The first step to any screening is otoscopy. By visualising the ear canal and ear drum the screener can check for wax occlusion, foreign objects, and ear infections. After otoscopy, the subject is ready for air conduction testing.
Air conduction
Air conduction exams test the whole hearing system at once. Headphones are either placed on or over the ear (or insert earphones are placed into the ear canal) so the person being tested can hear the sounds.
The sound wave travels though the outer ear canal, into the middle ear space, and into the inner ear organ - the cochlea - where the sound wave is converted into an electrical signal the brain can understand.
When the sound is presented, the patient is required to respond. Usually, the examiner will have the patient raise their hand or press a button.
Newborn hearing screening
Newborn hearing screening is a vital process aimed at identifying hearing impairments in infants shortly after birth. Early detection and intervention for hearing loss are critical because hearing plays a crucial role in a child's language development and overall communication skills.
Newborn hearing screening is typically performed within the first few days of a baby's life, ideally before they leave the hospital or birthing centre. There are two primary methods for newborn hearing screening:
Otoacoustic Emissions screening
Otoacoustic Emissions screening (OAEs) examines the function of the cochlea, by looking at the outer hair cell function. A probe microphone is inserted into the ear canal that plays sounds and records whether the hair cells echo a response back.
These screenings are often used for newborn hearing screenings or for children who are too young to participate in air conduction testing. OAE screening tests results are either a pass or a fail. A fail does not always mean that hearing loss is present, but it should always lead to a re-test or to a referral for more in-depth testing.
Auditory Brainstem Response screening
Auditory Brainstem Response (ABR) screening tests look at how the auditory nerve responds to a sound stimulus. For newborn hearing screening, the infant wears electrodes that are attached to their head and muff-style headphones are put on the ears.
When the sound is presented, a neural response is recorded. Like the OAE, the screenings are a pass/fail. ABR is the preferred newborn hearing screening test because it tests to the auditory nerve, whereas an OAE only tests to the cochlea.
Mild hearing loss can be detrimental to a child’s speech and language development, so it is vital that hearing continues to be screened throughout childhood. Hearing screenings for adults are important too, as more and more research indicates the importance of hearing and brain health. The earlier hearing loss is detected, the sooner it can be treated.
Child hearing screening
Air conduction screening tests for children start as early as four years old and are often performed in paediatrician’s offices, at school and sometimes at the child’s home. These tests can be performed by trained nurses, teachers, speech pathologists, volunteers and sometimes by audiologists, and are usually considered a pass or fail.
A headset that fits over the child’s ear is used to present the tones. A set intensity is usually chosen for children, such as 20 dB, and 4 frequencies are tested, usually 500, 1000, 2000 and 4000 Hz. If a child does not respond to one or more of the frequencies, they will be referred to an audiologist for more in-depth testing.
An important factor for accurate child screening is a quiet space with minimal distractions. A child may fail a test if the room environment is too noisy, or if they become distracted. Screening exams are important for children as they can be the first indicator of hearing loss, ear infections or other ear disorders.
Adult hearing screening
Adult screening test protocols vary depending on why they are being screened. Exams are performed by many different individuals and in many settings such as doctor’s offices, assisted living facilities, at work, and even at a patient’s home.
Occupational noise is the most common reason for adult screening. In many countries, if a workplace has noise environments of 85 dB or above for an 8-hour work period, hearing screening tests are mandatory for employees.
Testing for occupational noise requires threshold testing, meaning the patient must respond to the softest sound that they hear. Most often, 500, 1000, 2000, 3000, 4000 and 6000 Hz are tested. For this type of screening the tester is looking for hearing loss (threshold responses of 30 dB or larger) and threshold shifts (changes in hearing response 15 dB or larger).
Hearing screenings for adults can also be like those described for children as a pass or fail test. These determine if a patient needs to be referred to an audiologist for a diagnostic test and hearing consultation.
More and more people are now using online hearing tests. These are easy to access and often free. They can be a great screening tool, but it should be noted that they may not be as accurate as one would hope. Headphone calibration, noisy environments and many other factors can contribute to inaccurate results when using an online test. As with any other screening tests, if hearing loss is detected, it is always best to be seen by a hearing professional for a thorough diagnostic exam.
Screening audiometers
Our extensive range of dependable, accurate and PC-based screening audiometers are the prefect solution for newborn, child and adult hearing screening.
All our devices are portable and easy-to-use, providing a customised and flexible mobile or static solution. As well as providing hearing screening and data management solutions tailored to the user’s specific requirements, guaranteeing accurate and efficient testing.
For more information on our range of screening audiometers, please visit our audiometers webpage, contact our customer support team on +44 (0)1865 880 846 or email.
References
American Speech-Language Hearing Association. Hearing Screening. Accessed at:
https://www.asha.org/public/hearing/hearing-screening/
Centers for Disease Control Prevention (2018). Noise & Hearing Loss Prevention: Hearing Loss Prevention Programs. Accessed at:
https://www.cdc.gov/niosh/topics/noise/preventhearingloss/hearlosspreventprograms.html
Centers for Disease Control Prevention (2022). Screening and Diagnosis of Hearing Loss. Accessed at:
https://www.cdc.gov/niosh/programs/hlp/default.html
American Speech-Language Hearing Association. Adult Hearing Screening. Accessed at:
https://www.asha.org/practice-portal/professional-issues/adult-hearing-screening/
American Speech-Language Hearing Association. Types of Tests Used to Evaluate Hearing in Children and Adults. Accessed at:
https://www.asha.org/public/hearing/types-of-tests-used-to-evaluate-hearing/