Notchphase

Notchphase is a term used in signal processing and audio engineering to describe the behavior of the phase of a signal at or near a spectral notch. The term does not have a single, universally accepted definition; different sources use it to refer either to the phase response of a system that includes a notch or to the relative phase between spectral components surrounding the notch. In practice, notchphase concerns how phase varies as frequency approaches and passes through the notch frequency, and how this variation affects downstream processing.

The concept is most relevant when notch filtering or other sharp spectral attenuation is involved. Notch filters can introduce rapid phase changes near the notch center, which can influence time-domain characteristics, phase-sensitive demodulation, and coherence in multi-channel or stereo processing. Understanding notchphase helps engineers anticipate potential artifacts such as transient distortions or misalignment of phase across frequency bands.

Etymology reflects its components: notch refers to the spectral attenuation band created by the filter or system, and phase refers to the angular component of sinusoidal signals in the frequency domain. The term is primarily used in discussions of filter design, spectral analysis, and applications where precise phase behavior around a notch is important.

See also: notch filter, phase response, spectral notch, equalization, coherent processing. While notchphase appears in several technical discussions, its exact interpretation can vary by author, and practical use typically requires context from the surrounding analysis or design methodology.