15 results about "Zero-crossing rate" patented technology

The zero-crossing rate is the rate of sign-changes along a signal, i.e., the rate at which the signal changes from positive to zero to negative or from negative to zero to positive. This feature has been used heavily in both speech recognition and music information retrieval, being a key feature to classify percussive sounds. ZCR is defined formally as zcr=1/(T-1)∑ₜ₌₁ᵀ⁻¹𝟙ℝ<₀(sₜsₜ₋₁) where s is a signal of length T and 𝟙ℝ<₀ is an indicator function.