Pros and Cons
The tone and chirp MEPA reflectance curves are essentially the same (ie they usually overlay one another when tested in the same ear one after the other).
- Chirp: faster, with a broadband frequency range, but lower SNR (fine for adults).
- Tone: slower, tested only at specific frequencies (but over a wide range), but higher SNR (better for infants). Can be easier to analyze for group data analyses.
- You can design a chirp stimulus protocol to use longer averaging (e.g., 3 seconds instead of 1 second) to give better SNR.
- You can design a tone stimulus protocol that uses more, fewer, or different tones.
Tone and chirp comparisons are shown in various papers, including Hunter et al. (2010).
HearID MEPA provides tone stimuli, but OtoStat MEPA does not (this is because OtoStat uses the MEPA measurement to calibrate all the other tests, and this needs to be tested at all frequencies).