Acoustic, non-invasive measurement of velopharyngeal aperture using a high frequency tone

Abstract

Many researchers need access to the real time articulatory state of the velopharyngeal port to investigate the timing and extent of nasal gestures alongside the acoustic consequences of those gestures. While numerous methods exist for the investigation of nasalization (e.g., airflow, velotrace, and nasometer), these methods tend to be invasive, expensive, or to muffle the acoustic speech signal in pursuit of nasal articulatory data. We describe an inexpensive method and procedure for the investigation of nasal gestures using low frequency ultrasound. This system injects a 20 kHz tracer tone into a nostril using inexpensive components and/or three-dimensional printed parts. This signal can then be collected along with the speech signal using microphones typical in speech research. We will compare the results of this system to those of a state of the art airflow collection system and compare cross-participant reliability of both methods. Many researchers need access to the real time articulatory state of the velopharyngeal port to investigate the timing and extent of nasal gestures alongside the acoustic consequences of those gestures. While numerous methods exist for the investigation of nasalization (e.g., airflow, velotrace, and nasometer), these methods tend to be invasive, expensive, or to muffle the acoustic speech signal in pursuit of nasal articulatory data. We describe an inexpensive method and procedure for the investigation of nasal gestures using low frequency ultrasound. This system injects a 20 kHz tracer tone into a nostril using inexpensive components and/or three-dimensional printed parts. This signal can then be collected along with the speech signal using microphones typical in speech research. We will compare the results of this system to those of a state of the art airflow collection system and compare cross-participant reliability of both methods.