Understanding Hearing Loss: An Audiology Primer For University Students

Audiology is the study of hearing and balance systems and the disorders relating to them. In the US, a Doctor of Audiology (Au.D.) is the standard entry-level credential in the field. A doctorate in audiology can lead to jobs in hospitals, schools, and clinics. The program typically requires four years of full-time study beyond a bachelor's degree. It involves substantial coursework in relevant science fields like acoustics and aural rehabilitation, as well as clinical placements and research opportunities. Audiology students learn to diagnose and treat hearing and balance disorders, and counsel patients on coping with these problems.

Hearing and balance disorders

Hearing loss among college students, specifically noise-induced hearing loss (NIHL), is increasing. College students are required to listen to lectures in classrooms that may have suboptimal listening environments. College-aged musicians are at a high risk of NIHL due to repeated and extended exposure to loud noise. The prevalence of hearing loss in college students is 19%, and 85% of student musicians experience hearing loss at 6000 Hz.

NIHL is caused by exposure to loud noise, defined as any noise over 85 dBA that someone is exposed to for more than 8 hours. Temporary NIHL can occur within minutes of exposure to loud noise, and extended exposure can lead to complete destruction of the outer and inner hair cells, resulting in cell death. NIHL typically forms a noise "notch" in an individual's hearing abilities, most commonly observed in high frequencies.

College students with hearing loss may have difficulty performing in class due to decreased attention, comprehension, and memory. Implementing hearing conservation programs and early detection of hearing loss at 6000 Hz can help prevent hearing loss in students, especially collegiate musicians.

In addition to hearing loss, tinnitus is a common otological condition that affects college-aged individuals. Tinnitus is associated with noise exposure and can impede daily functioning, sleep, and emotional state.

Hearing aids and cochlear implants

Hearing loss is a common issue, with about 20% of the world's population experiencing it in 2019. Hearing aids and cochlear implants are two solutions to this problem, but they work in different ways and are suitable for different types of hearing loss.

Hearing aids are non-surgical devices that amplify acoustic sound generally and/or by specific frequencies. They are best suited for people with less severe hearing loss and fair speech understanding. Hearing aids are typically easier to adapt to than cochlear implants, taking around two weeks or less.

Cochlear implants, on the other hand, require surgery and are more suitable for people with severe hearing loss in one or both ears and poor speech understanding. Cochlear implants bypass the damaged portions of the ear and directly stimulate the auditory nerve. The signals generated by the implant are then sent to the brain, which recognises them as sound. This process of learning or relearning hearing takes time and can take up to 12 months.

Both devices can help people with hearing loss to communicate better, but a thorough evaluation is required to determine which option is best for an individual.

Anatomy and physiology of the human auditory system

The human auditory system is made up of peripheral and central auditory structures. The peripheral structures include the outer, middle, and inner ear. The central structures include the cochlear nuclei, superior olivary nuclei, lateral lemniscus, inferior colliculus, medial geniculate nuclei, and auditory cortex.

Sound waves reach the outer ear and travel down the external acoustic meatus to the tympanic membrane, causing it to vibrate. These vibrations are transmitted to the middle ear, which consists of three small bones (ossicles): the malleus, incus, and stapes. The ossicles amplify the sound and transmit it to the inner ear.

The inner ear is filled with fluid and contains the cochlea, a long coiled tube divided into three chambers: the scala vestibuli, scala tympani, and scala media. The cochlea houses the organ of Corti, which contains hair cells that respond to sound. The hair cells have stereocilia that connect to a tectorial membrane. When sound waves cause the basilar membrane to vibrate, the stereocilia bend and open ion channels, converting sound energy into electrical energy and nerve signals.

The auditory nerve transmits these signals to the brain via the central auditory pathways, which include the cochlear nuclei, superior olivary complex, lateral lemniscus, inferior colliculus, and medial geniculate nuclei. These pathways encode sound frequency, intensity, and spatial location, allowing individuals to understand and interpret sounds accurately.

The auditory cortex, located in the temporal lobe, is responsible for conscious awareness of sound. It receives input from the medial geniculate nuclei and plays a crucial role in higher-level auditory processing, including speech and language comprehension.

Audiology careers and job outlook

Audiology is a growing profession, with a projected expansion of career opportunities for audiologists over the next decade and beyond. This growth is mainly due to the increasing number of older people, people living longer, and the link between hearing loss and aging. Audiology focuses on patients' ear problems, including hearing loss and balance disorders. Audiologists often work directly with patients to diagnose and treat them, but they can also find other opportunities to promote auditory health.

Career Options

There are several career options within the field of audiology, including:

• Clinical audiologist: These professionals examine, diagnose, and treat patients of all ages or specialize in a particular group, such as children or the elderly. They use various equipment and testing techniques to develop personalized treatment plans, which may include fitting patients with hearing aids or cochlear implants, or recommending medications for minor hearing issues.
• Pediatric audiologist: A pediatric audiologist specializes in treating patients under the age of 21, from infants to teenagers. They help individuals and families detect hearing loss and other auditory issues early on and develop treatment plans, such as hearing aids or specialized therapy.
• Educational audiologist: An educational audiologist provides auditory healthcare services to children, focusing on how their educational environment supports their needs. They work with school staff to improve accessibility and develop individualized education programs (IEP) for students.
• Humanitarian audiologist: Humanitarian audiologists serve individuals who don't have access to health services that support their auditory needs. They often find employment through non-profit organizations and may travel globally to help communities.
• Forensic audiologist: Forensic audiologists specialize in using their expertise for legal purposes, such as assessing individuals seeking compensation for hearing loss caused by their workplace.
• Corporate audiologist: Corporate audiologists often work for organizations that create and sell hearing devices or technologies. They use their expertise to advise during product development and oversee clinical trials.
• Audiology assistant: Audiology assistants work alongside audiologists, helping with patient care activities, setting up and cleaning equipment, performing hearing tests, and providing guidance on hearing aids.

Education and Training

To become an audiologist, one must typically obtain a Doctor of Audiology (Au.D.) degree, which takes around four years of full-time study beyond a bachelor's degree. The Au.D. program provides a solid foundation in the science of hearing and the skills to conduct and promote evidence-based clinical practice. It includes a combination of academic and clinical education, as well as research participation. During their studies, aspiring audiologists may take courses in anatomy and physiology, diagnosis and treatment, and statistics, in addition to completing supervised clinical practice.

Job Outlook

The U.S. Bureau of Labor Statistics projects a 13% growth in employment for audiologists from 2019 to 2029, which is much faster than the average for all occupations. This demand is attributed to the aging population, as older adults are more likely to experience hearing and balance issues. Innovations in hearing aid design also contribute to this growth, making these devices more appealing to patients of all ages.

The median salary for audiologists in the U.S. was $81,030 in 2020, with a projected median annual wage of $87,740 in 2023.

Audiology research and innovation

Audiology is a growing field, with a rising number of jobs and a high demand for graduates. The Doctor of Audiology (AuD) is the standard entry-level credential in the field and is now a requirement for clinical practice. The AuD program provides a solid foundation in the science of hearing and the skills to conduct and promote evidence-based clinical practice.

The University of South Florida (USF) offers a four-year, full-time, 120-credit residential program with comprehensive coursework, clinical placements, and research opportunities. The program includes academic coursework, clinical practica, a doctoral research project, comprehensive examinations, and a national examination in Audiology. USF also offers a dual-degree program, combining the AuD with a Doctor of Philosophy (PhD), which can be completed in approximately six years. This dual-degree program is designed for those interested in clinical research and independent research in their chosen area of hearing science and clinical audiology.

Purdue University also offers a Doctor of Audiology program, which is accredited and provides students with hands-on experience in the Purdue University M.D. Steer Audiology Clinic. The program includes research opportunities in areas such as computational modelling, neurophysiology, and auditory cognitive neuroscience.

The scope of practice in audiology has expanded significantly since the 1960s, and the academic and clinical training requirements have increased from a master's degree to a professional doctorate. The AuD program typically requires four years of full-time study beyond a bachelor's degree, and graduates are prepared for independent clinical practice in areas of auditory and vestibular assessment and treatment.

The traditional PhD in Hearing Science or Audiology includes advanced coursework in auditory neuroscience, audiology, statistics, research design, instrumentation, and computer science. Clinical PhD programs combine the coursework and clinical training required for audiology practice with the research experience of a traditional PhD. Graduates of clinical PhD programs are also eligible for licensure in audiology in most states and are qualified to work in academic and research settings, as well as in government, medical, community-based, and industrial settings.

Frequently asked questions