Sampling and zero crossing

1. What is zero-crossing in sampling?
2. What is a zero-crossing in sound?
3. What is a zero-crossing event?
4. What is cross over current and when it is zero?

What is zero-crossing in sampling?

A zero-crossing is a point where the sign of a mathematical function changes (e.g. from positive to negative), represented by an intercept of the axis (zero value) in the graph of the function. It is a commonly used term in electronics, mathematics, acoustics, and image processing.

What is a zero-crossing in sound?

The zero-crossing rate (ZCR) is the rate at which a signal changes from positive to zero to negative or from negative to zero to positive. Its value has been widely used in both speech recognition and music information retrieval, being a key feature to classify percussive sounds.

What is a zero-crossing event?

rising — A zero crossing occurs when a signal rises to or through zero, or when a signal leaves zero and becomes positive. falling — A zero crossing occurs when a signal falls to or through zero, or when a signal leaves zero and becomes negative.

What is cross over current and when it is zero?

In alternating current, the zero-crossing is the instantaneous point at which there is no voltage present. In a sine wave or other simple waveform, this normally occurs twice during each cycle.