Researchers at the university of Aix-Marseille have recently developed a silent device to measure the air pressure inside an airtight sealed external auditory ear canal. The pressure sensor can detect contractions of the tensor tympani (a muscle in the middle ear) via the changes in pressure produced by tympanum movements. It can potentially provide objective data for patients whose hyperacusis involves the middle ear (and more specifically the tensor tympani muscle).
The device is still experimental and can be used as an objective supplement for the assessment of hyperacusis, but does not replace other tests. The sensor itself does not emit any sound and only detects tympanum movements, but sometimes a sound stimulation is needed to trigger the tensor tympani contraction. In some other people, the tensor tympani can be contracted at will. For others, this can happen when trigger points are stimulated, during somatic manoeuvers of the head (rotation of the head...), during swallowing or sometimes even spontaneously.
These two scientific studies explain the pressure sensor in more detail:
To our knowledge, in Belgium this device is only used in the Luisterkliniek in Ghent. A clinic dedicated to hyperacusis and pain hyperacusis is currently being set up at Lariboisière Hospital in Paris.