Calibrate Acoustic Reflectometer

[Roberts_Curiosity]

I  want to buy whatever is necessary to calibrate an Acoustic Reflectometer.
As best I can figure, such a calibrator would need an artificial ear that can simulate
both a healthy and diseased tympanium (as in an "ear drum").

Any pointers or advice greatly appreciated. 

I asked over in the metrology forum, and got no response. 

Thanks, Bob

[_Wim_]

Maybe this patent can give some ideas:

https://patents.google.com/patent/US20100087751A1/en

I do not know anything about this topic, your question just made me curious for what exact an Acoustic Reflectometer was used...

[1audio]

I could not find a reference to a specific product online. No way to find a manufacturer or datasheet.  The technology looks quite interesting and is being used for finding problems with piping and other similar applications as well as hearing.

I would suggest contacting the manufacturer for calibration info. Its very similar to a TDR. You could calibrate it with several tubes and caps for a "short" or 100% reflection and cap off for an open for an inverted reflection. And maybe some cotton balls in the end of the tube for 100 & absorption. Different length tubes for distance calibration.  This may help : https://hvtechnologies.com/the-basics-of-time-domain-reflectometry-tdr/ 

[Inside21]

manufacturer - Bruel & Kjaer
https://www.bksv.com/en/transducers/simulators/ear-mouth-simulators
best regards

[Roberts_Curiosity]

Thanks for the pointer.
I saw a lot of stuff for testing headphones, earphones and hearing aids.
I could not find where Bruel & Kjaer has anything to calibrate an acoustic reflectometer.
What did I miss? 

[DaJMasta]

I don't really know what you're expecting to calibrate, but if you can identify what the calibration should be performed to, that will help.

My assumption is that for a device meant for measuring such a variable setting will be performing only relative measurements, and will only either work reliably as a diagnostic tool, with a direct comparison from the same healthy subject, or when the difference in measurement is so obviously different that it probably doesn't need calibration.  If you want to calibrate the output or input to known references (frequency, power, etc.), standard acoustic calibration equipment will probably suffice, but if you need to reference to a model, well you're going to have to find one of the models that it was originally designed for.  But to confirm, do you actually have evidence that it requires calibration?  Have you found any documentation or menu options that mention calibration, zeroing, or comparing to some known reference as a check?



As it is a medical device, you may be better off asking a community of doctors, pediatricians, or audiologists who is actually familiar with the operating procedure.  Otherwise, providing specifics of what it is, what documentation it has, what it's actually measuring, etc. to get reasonable replies.  It's obscure enough and out of the range of normal test equipment enough (at least for an electronics forum), that I doubt many people here have any clear idea of what you're actually even working with.