Technical Report

Ghio A., Teston B., (2004) "Evaluation of the acoustic and aerodynamic constraints of a pneumotachograph for speech and voice studies", International Conference on Voice Physiology and Biomecanics, Marseille, France, August 18-20, 2004, p.55-58

Ghio A., Teston B. (2002) "Caractéristiques de la dynamique d'un pneumotachographe pour l'étude de la production de la parole: aspects acoustique et aérodynamique", 24èmes Journées d'Etudes sur la Parole (JEP), Nancy, France, p.337-340

Hautefeuille, M. (2003). Calibration statique et dynamique du système de mesures aérodynamiques EVA.: Stage 1ère année Ingénieur, ENSERG - Institut National Polytechnique de Grenoble.

Specs

Most of the sensors are fixed on a device called "mouthpiece "(patented device):

Subject position to record acoustic and aerodynamic data with the "mouthpiece"

The oral airflow measurement needs a mask. Three mask sizes are available : large, medium and small. Masks are made with silicone. Flexible and pleasing to the skin, they allow a good airtightness and can support cleaning agents.

The nasal airflow sensor is placed vertically below the nostrils. Such a system allows a natural conduction of the air (patented device). Different sizes of tubes are available, according to the subject nostrils. They can be dismantled to be cleaned.

Pressure can be measured using a catheter connected to the pressure sensors integrated in the mouthpiece. Intra-oral pressure can be directly measured by slipping the catheter between the lips or through nasal tract. Sub-glottic or oesophagian pressure can be measured simultaneously using an other catheter.

The EVA2™ system measures airflow using a wide-range, grid pneumotachograph featuring low dead space and high linearity. With a 1 l/s airflow, grid resistance is about 10 Pa, which is equivalent to 1/100 of a standard sub-glottic pressure (10 hPa). So, the load caused by the grid is very low. The measure can be done in expiration, but also in aspiration.

Technical specifications of pressure sensors are

piezoresistif bridge

heat and gravity compensation

response time : 0.1 ms

linearity (typical : 0.01%, max. : 0.1%)

damage pressure : 1900 hPa