Inventis Trumpet • Occluded, Aided and MPO measurements

Inventis Trumpet • Occluded, Aided and MPO measurements


Welcome to the Trumpet tutorial video series. In this video, we will go through the key
measures for a hearing aid verification and fitting protocol. With OCCLUDED, we will see how the ear-canal response is modified when we put in place the hearing aid, while with Aided and MPO,
we will get the information for a fine tuning of the amplification provided. To start, double click on the Maestro icon
and the software will open. Exams available will be shown on the upper
part of the software. Select REM to access the in-vivo tests, and
then choose OCCLUDED. Please note that the acquired measurements, can
be represented either as the signal caught by the probe microphone, called RESPONSE, or, as a differential value between the probe and reference captured signal, called GAIN. During this video series, all examples will
be displayed as GAIN. In the case of OCCLUDED measurement, the patient
should wear the hearing aid, but turned off. The probe tubes should be inserted in the
ear canal reaching a few millimetres distance from the eardrum, so that we can measure
the occlusion effect due to hearing aid insertion. In the upper left panel, a dropdown list allows to select the stimulus to send as input to the loudspeaker. By pressing play button, the acquired curve will
be displayed on the graph, but not recorded. So that the probe can be adjusted until the
positioning achieved is correct. When you trust that the acquired curve is ok, it can be easily recorded by pressing the record button. The values will be kept in the software and
displayed on the graph. Now, move to AIDED, and turn on the hearing aid. Before starting, the software requires the
match of a pure tone audiometry. Drag it from the exam bar at the bottom of
the page, and drop it on the graph. The prescription curve will be displayed as a dashed line, according to the stimulus intensity selected. Alternatively, the Pure Tone audiometry can
be browsed and selected from a dropdown list available from the REM Menu. In this section, up to five curves can be recorded choosing different intensities and stimuli. The first three: Soft, Medium and
Loud sounds, is what is usually suggested. Once the measure has started running, using the ON TOP MODE, it is possible to display the AIDED gain while adjusting the hearing aid parameters
through its own software. In this way, it is much easier to set the
hearing aid amplification in accordance to the prescription curve. Please be aware that if you have a hearing aid
with an open dome, you should first select the Open Fit option. The system will then ask to perform an extra
measurement with the hearing aid turned off, in order to avoid a feedback loop. MPO mode is dedicated to the Maximum Power
Output measurements. Considering the values of the previously matched PTA, the software calculates and shows the patient discomfort threshold as a dashed line. Then, a tone sweep at 85 dB has to be reproduced, so that it is possible to see if the hearing aid maximum amplification creates discomfort to the patient. The resulting curve should lay below the dashed line. In MPO it is also possible to select the ON
TOP MODE, and easily modify the hearing aid parameters to avoid crossing the discomfort threshold when the tone sweep is produced.

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