Tympanometry is a routine yet powerful tool for assessing middle ear function. However, even the most advanced equipment can't compensate for a poor seal—accuracy depends on it. While audiologists are well aware of this, many trained professionals in diverse settings, such as pediatric clinics, schools, and newborn screening programs, also perform tests that require a proper seal. This blog will guide you through best practices to ensure a reliable seal during tympanometry and OAE testing, helping you avoid misdiagnosis and repeat procedures.
Clinical Consequences of a Poor Seal
An inadequate seal can produce flat or distorted tympanograms that mimic middle ear pathologies such as otitis media with effusion, tympanic membrane perforation, and ossicular discontinuity. This can lead to false positives, prompting unnecessary referrals, imaging, or medical treatment. In addition, a poor seal may also mask true pathology, resulting in false negatives and delayed intervention.
Inaccurate Middle Ear Pressure and Compliance Readings
Without a stable pressure environment, the tympanometer cannot accurately measure the peak pressure, static admittance, and tympanometric width. These metrics are essential for diagnosing conditions like Eustachian tube dysfunction or hypermobility of the tympanic membrane. Inaccurate readings compromise your ability to make informed clinical decisions.
Compromised Pediatric Assessments
Children are particularly sensitive to discomfort and movement during testing. A poor seal in pediatric patients may increase the test time, ultimately reducing cooperation. The window that is available to test a pediatric patient is often small, which is why it’s crucial to move quickly and accurately.
Best Practices for Achieving a Reliable Seal
1. Select the Correct Probe Tip: Ear tip selection is more than just ensuring patient comfort, it’s about precision. Use an ear tip that fits snugly in the ear canal without causing discomfort. Most tympanometers offer a range of sizes; don’t hesitate to switch if the seal isn’t holding. In addition, use high quality ear tips!
2. Position the Ear Properly: Gently pull the pinna upward and backward to straighten the ear canal. This simple maneuver can significantly improve the likelihood of a good seal, especially in younger patients.
3. Stabilize the Probe: Ensure the probe remains steady throughout the test. Movement, even subtle movement, can break the seal and invalidate the results. For children, consider using distraction techniques to minimize motion.
4. Watch the Pressure Trace: Modern tympanometers provide real-time feedback. A flat or erratic trace often signals a leak. Use this as a cue to reassess the seal before interpreting the results.
5. Re-Test When in Doubt: If the tympanogram doesn’t match the clinical picture, don’t hesitate to re-test. A second attempt with a better seal can clarify findings and prevent unnecessary referrals.
Pediatric Considerations: Children present unique challenges. Their smaller ear canals and limited tolerance mean the quality of the seal is even more critical. Use age-appropriate ear tips, engage them with toys or videos, and be patient.
Establishing a proper seal is a critical skill for professionals conducting hearing screenings, as it directly influences the accuracy of test results. By focusing on seal quality, trained technicians working in pediatric clinics, schools, and hospitals can ensure dependable data, minimize the need for retesting, and support better outcomes in patient care.
Laura Prigge, AuD is the Manager of Clinical Education and Training at GSI. Laura received her Doctorate of Audiology degree from AT Still University, a Master's of Arts in Audiology from UCONN and a Bachelor's of Science degree in Communication Disorders from Western Illinois University. Laura’s 20+ years of experience includes providing manufacturing support for a leading hearing aid manufacturer as well as technical audiology training and support for an international audiologic equipment company. Prior to that, she managed education and training at another hearing aid manufacturer and conducted audiologic evaluations on children, adults, and geriatric patients at a retail hearing center.