TEOAE Measurement Module FAQ
Q: How often do I need to run the In-The-Ear calibration?
A: You need to run the In-The-Ear calibration before each measurement.
Q: Sometimes a very large response swamps the TEOAE measurement, but it doesn't appear to be related to noise.
A: This issue occurred in HearID R3.3.5 or earlier, on some slow computers. Contact Mimosa for an upgrade to version 3.3.6.
Q: Are my old TEOAE protocols from R3.2-R3.4 compatible with HearID 5?
A: Yes, but with caveats. There is an upgrade path for the old protocols. When you copy the old protocol over and the run HearID, HearID will convert it to the new format. Stopping rules and Pass/Refer rules have been extensively upgraded in HearID 5 to provide easier and more flexible customization. HearID will try to match the old rules as closely as possible but it is not logically possible to recreate them exactly under all circumstances. Furthermore, the gain setting is dropped from 40 dB to 20 dB. This greatly reduces the chances of clipping. It may be manually changed if desired. Once you have upgraded the protocol, verify the settings are as intended. If you experience any difficulties, please contact Mimosa.
Q: I get a calibration error when measuring infants, children, or adults with small ear canals. The noise rejection bar turns red and no data is collected.
A: This issue sometimes occurs in HearID R3.2-3.4 when using the HearID PC-card. The measured response to the calibration stimulus in the ear canal is too large for the default gain setting of 40 dB so the response is clipped and the data discarded. Change the "A/D input" gain setting found in the TEOAE measurement parameters window to 20 dB and save the protocol with a different name. HearID 5 uses a 20 dB default setting.
Q: How do I export TEOAE data for use in Matlab?
A: To export TEOAE data to a Matlab mat file, please see Section 2.6.9 in the TE Manual. The resulting *.mat file has the structure "res", the details of which are specified in Appendix B of the manual. The data generated by this operation is identical to the displayed data. An alternative is to export the raw (unprocessed) buffers to a txt file, the details of which are also in Section 2.6.9. This option is preferred if you wish to completely reprocess the measurement using your own response filter and window. In HearID 5, TEOAE data is automatically exported when saving each measurement.
The TestHistory table in the HearID database contains the filename for the original TEOAE measurement (saved in a binary format as a *.tdt file). When the data are exported, the same file prefix is used and a datetime stamp is added. For instance 0022_R_TEOAE_20070327110602.tdt is exported as 0022_R_TEOAE_20070327110602_data_20070327T115128.mat. To fully exploit the information contained in the HearID database, use the database toolbox in Matlab to query the HearID database for the filenames (and any other relevant information, like PatientID, ear, etc.) and use regexprep to generate the filenames of the exported file (with a * for the unknown datetime stamp: 0022_R_TEOAE_20070327110602*.mat), then use "dir" to find all files matching that name.
Q: I am running the HearID system with the HearID PC-card and the MEPA and/or TE modules, and I am getting an "HID-board error" that reads "Av-error:Buffer size mismatch". What should I do?
A: Using the installation CD, choose the update feature to repair your drivers.
