High-precision temporal measurement of vibro-acoustic events in synchronisation with a sound signal on a touch-screen device

A method for determining the tap times of a user in response to an auditory stimulus, the method comprising:

• playing back the auditory stimulus, the auditory stimulus corresponding to a reference audio signal (SR);
• recording the reference audio signal (SR) and one or more vibro-acoustic events (eva), the vibro-acoustic events (eva) being subsequent to one or more taps by the user on a touchscreen of a touchscreen device in reaction to the reference audio signal (SR), resulting in a recorded audio signal (SE), wherein the recorded audio signal (SE) is recorded with a microphone of the touchscreen device:
• detecting the reference audio signal (SR) in the recorded audio signal (SE)
• the method further comprising
• placing the reference audio signal (SR) and the recorded audio signal (SE) on a single common time scale;
• filtering the recorded signal obtained subsequently and normalizing the recorded signal in such a way as to keep only the frequencies corresponding to the vibro-acoustic events (eva) generated by the actions of the user on the touchscreen;
• and
• detecting vibro-acoustic events (eva) in which instants (ti) associated with the vibro-acoustic events (eva) are identified in the signal obtained.