Diagnosing hearing loss takes the skill of a trained hearing care professional who is equipped with the right tools. For many, pure tone audiology stands as the gold standard of audiologic exams. We'll explore why this versatile test is used by so many hearing care professionals and what you need to implement it at your clinic.
What Is Pure Tone Audiology
Pure tone audiology is used to determine a patient's hearing acuity. Specifically, this air conduction test determines the faintest tones a person can hear at different pitches. In this way, it does more than simply confirm a hearing loss diagnosis. Pure tone audiology tests can reveal the type of hearing loss and the severity of the patient's condition.
How Is a Pure Tone Audiometry Screening Conducted?
Pure tone audiometry uses pure tones played at different pitches to determine hearing acuity. Sounds at different pitches are played at varying volumes. The hearing care professional determines when the individual can no longer hear the tone. With the information, the hearing care professional can identify the decibel when the person can no longer hear a particular frequency.
Next, the process is repeated using sounds at different pitches. The exam data appears on an audiogram that shows the participant's hearing function across a range of pitches and decibels. The practitioner will compare the audiogram with commonly accepted hearing norms to determine the amount of hearing loss.
Equipment Needed For a Pure Tone Audiometry Screening
There are various ways to conduct a pure tone audiology screening. Equipment may include the following:
- Headphones: Circumaural headphones are used to reduce ambient noise. They fit snugly around the ear. Supra-aural headphones rest on the ear. They do not reduce ambient noise and may collapse the ear canal.
- Insert earphones: Insert earphones fit inside the ear canal. Small transducers transmit signals through a tube to foam tips. This style of earphones decreases collapsing ear canals and reduces ambient noise. Insert earphones can also prevent the crossover of auditory stimuli to the non-test ear.
- Speakers: Used for sound-field testing, speakers present the auditory signals to the participant without need for earphones. Instead of pure tones, the auditory signals are warble tones or bursts of narrow-band noise. The speaker is usually positioned at a 45-degree azimuth to the individual's face. This type of testing is used for those who cannot tolerate earphones — such as infants, toddlers, and people with developmental disabilities. The participant sits in the center of a room, halfway between each speaker. Visual-reinforcers, such as toys and lights, are usually used in conjunction with sound-field testing.
- Bone-conduction oscillator: This device is used to bypass the outer and middle ear, instead transmitting the signal through the skull to the cochlea. The oscillator is usually placed on the mastoid bone or, occasionally, the forehead. The oscillator stimulates the skull, which then stimulates both cochleae.
- Audiometer: The audiometer produces the audiogram at the conclusion of the test. Pure tone audiometers are also used to change the stimulus level, turn the signal on or off, and send the sound to the appropriate transducer: earphones, bone oscillators, or speakers.
Benefits of Pure Tone Audiometry
Pure tone audiometry offers accurate results as well as information from each ear that allows hearing care professionals to recommend further testing or appropriate treatment. Most tests are completed in less than 30 minutes. Little equipment is needed to conduct this type of screening, so cost of entry is quite low.
About the Author
Adam is the Digital Marketing Coordinator at e3 Diagnostics. His interest in hearing healthcare is driven by his passion for music because he feels everyone should be able to clearly listen to Pet Sounds at least once in their life. In his free time, he enjoys playing video games, digging through record stores for classic vinyl, shooting hoops, and writing stories.