A method for sensing touch inputs to a digital equipment is provided, comprising the steps of sensing a sound / vibration
signal generated by a touch, digitally
processing the sensed sound / vibration
signal, and determining the type of touch means that has generated the touch and the intensity of the touch based on the properties of the processed sound / vibration
signal, wherein the properties include at least one of the following properties of the sound / vibration signal in
time domain:
maximum amplitude, average amplitude, average frequency, mean, standard deviation, standard deviation normalized by overall amplitude, variance, skewness, kurtosis, sum, absolute sum,
root mean square (RMS),
crest factor, dispersion, entropy, power sum,
center of mass, coefficients of variation, cross correlation, zero-crossings,
seasonality,
DC bias, or the above properties computed for the first, second, third or higher order of derivatives of the sound / vibration signal; and the following properties of the sound / vibration signal in
frequency domain:
spectral centroid,
spectral density,
spherical harmonics, total average spectral energy, band energy ratios for every
octave, log spectral band ratios,
linear prediction-based cepstral coefficients (LPCCs), perceptual
linear prediction (PLP) cepstral coefficients, mel-frequency cepstral coefficients, frequency topology, or the above properties computed for the first, second, third or higher order of derivatives of a
frequency domain representation of the sound / vibration signal. There is also provided a device for sensing touch inputs.