Aero-tactile integration in fricatives: converting audio to air flow information for speech perception enhancement

We follow up on research demonstrating that aero-tactile information can enhance or interfere with accurate auditory perception among uninformed and untrained perceivers [1, 2, 3]. We computationally extract aperiodic information from auditory recordings of speech, which represents turbulent air-flow produced from the lips [4, 5]. This extracted signal is used to drive a piezoelectric air-pump producing air-flow to the right temple simultaneous with presentation of auditory recordings. Using forced-choice experiments, we replicate previous results with stops, finding enhanced perception of /pa/ in /pa/ vs. /ba/ pairs, and /ta/ in /ta/ vs. /da/ pairs [1, 6, 2, 3]. We also found enhanced perception of /fa/ in /ba/ vs. /fa/ pairs, and /sha/ in /da/ vs. /sha/ pairs, demonstrating that air flow during fricative production contacting the skin can also enhance speech perception. The results show that aero-tactile information can be extracted from the audio signal and used to enhance speech perception of a large class of speech sounds found in many languages of the world.