Transient Evoked Otoacoustic Emissions/TEOAE
Purpose
Test Outer Hair Cell functionaligy
Materials
TEOAE test equipment
Procedures/Instruction - Place Probe in Ear, Calibrate, Run Test
Place probe tip in ear, calibrate, run test
Capella
Capella
- Open Noah
- Select Otometrics
- Choose TEOAE
- Run for each ear twice, removing the probe each time
- Record measureements
- Open program
- Select patient
- Select TEOAE Test
- Run test in each ear twice, fully removing the probe each time
- Record results
Interpretation/Site of Lesion - Cochlea; Outer Hair Cells
Cochlea, outer hair cells at frequency specific location
TEOAE Testing Parameters
Test stimuli parameters for TEOAEs are typically fixed on most clinical equipment and offer very few parameters that can be adjusted. In some cases, the number of samples obtained, stopping criteria, rejection threshold, and stimulus intensity can be adjusted as needed.
Interpretation of TEOAE recordings
TEOAE recordings are commonly displayed using a table of values, a graphical display of two bins of averaged waveforms (intensity of the emission as a function of time) elicited by the stimulus, and a graphical display of the intensity of the sound measured in the ear canal as a function of frequency.
Two types of outcomes can be evaluated with TEOAEs. An overall assessment of the presence of an OAE response can be determined, or the response can be divided into frequency regions to be more discretely evaluated.
In addition, there are two values that can be used to determine the presence or absence of a TEOAE response. One value of importance is the reproducibility of the response. Each consecutive recording of the response is stored in one of two "bins." The responses are then compared to determine the percentage that is the same, or reproducibility, between the two responses. In addition, the levels of the TEOAE and the nose floor levels are used to determine whether the TEOAE must be sufficiently intense to be considered a potential TEOAE and must be sufficiently higher than the noise floor to be considered present and not just a signal occurring randomly in background noise. The particular levels that allow a clinician to make that judgement depend on the normative data for the equipment and clinical population of interest.
Two types of outcomes can be evaluated with TEOAEs. An overall assessment of the presence of an OAE response can be determined, or the response can be divided into frequency regions to be more discretely evaluated.
In addition, there are two values that can be used to determine the presence or absence of a TEOAE response. One value of importance is the reproducibility of the response. Each consecutive recording of the response is stored in one of two "bins." The responses are then compared to determine the percentage that is the same, or reproducibility, between the two responses. In addition, the levels of the TEOAE and the nose floor levels are used to determine whether the TEOAE must be sufficiently intense to be considered a potential TEOAE and must be sufficiently higher than the noise floor to be considered present and not just a signal occurring randomly in background noise. The particular levels that allow a clinician to make that judgement depend on the normative data for the equipment and clinical population of interest.
Management
References
Gelfand, Stanley A. Essentials of Audiology. Thieme, 2016.
DeRuiter, Mark, and Virginia Ramachandran. Basic Audiometry Learning Manual. Plural Publishing Inc., 2017
DeRuiter, Mark, and Virginia Ramachandran. Basic Audiometry Learning Manual. Plural Publishing Inc., 2017