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Department of Engineering, ICT and Technologies for Energy and Transport Patent Title Apparatus for clinical­audiometric investigation. Ref. CNR 10179 Assignee(s): CNR CNR Institute: IDASC Main Inventor: Domenico Stanzial Countries: EP Priority date: 03/01/2012 Abstract The present invention refers to a device that consists of a broadband acoustic stimulator and a micro­probe able to transduce the pressure and acoustic velocity (p­v) signals simultaneously. These sub­systems are all assembled in a headset adapter to be applied at the entrance of the ear canal. The p­v signals are then sampled and undergo a two­channel original digital post­processing. This computation gives the reliable and accurate measurement of sound energy quantities characterizing the immittance and acoustic absorbance of outer and middle ear. Obtained results are then graphically rendered for clinical diagnostic investigations in the audiometric field. The system can be used also for the recording and analysis of oto­acoustic emissions. Background The measurement of the ear­canal impedance, also called "tympanometry“, allows to make an objective analysis of the functional state of the outer and middle ear, in order to diagnose major diseases. The tympanometric test is currently conducted with indirect measurements using single­frequency stimuli and with an invasive method (artificial variation of the static pressure in the ear canal) that is particularly troublesome, especially in newborn and child aged subjects. Technology The microprobe used for the direct measurement of acoustic impedance inside the ear canal is based on MEMS technology, both for the microphone (pressure) signal and the velocimetric sensor. The latter, in particular, is manufactured with a standard CMOS process that greatly reduces the cost of production and makes it commercially attractive. Advantages and Applications Wideband tympanometry when carried out with direct measurements of the pressure and particle velocity signals makes the audiometric test rapid, complete, accurate, repeatable and non­invasive. The p­v measures are carried out at ambient pressure without annoying static pressure changes in the patient’s ear­canal and so making audiometric testing not only more reliable but also easy to perform and therefore convenient for self­diagnosis or telemedicine applications. Development stage The invention is currently in the stage of hardware prototype, being adapted to a generic two­channel acquisition system and p­v signals post­processing. Validation tests and clinical­diagnostic interpretation of the obtained results have not yet been performed. Only comparison measures with the data obtained by 13 standard tympanometers have been carried out.