The crossing of the horizontal axis by a mathematical function as it passes through zero and changes sign; a point where this occurs; frequently attributive.
The analysis of zero crossings is often an important activity in the study of complex waveforms, as is done in the fields of acoustics, electronics, and image processing.
1941
Equalization of adjacent harmonics insures that the zero crossings of Fig. 6 are equally spaced.
U.S. Patent 2,266,802 2/2
1969
Equipment capable of analysing and recognizing speech..has achieved considerable success using the so-called zero crossing technique.
New Scientist 1 May 225/1
2012
The zero crossings of the click response are not equidistant.
zero crossing typically occurs about 0.2 times per million words in modern written English.
zero crossing is in frequency band 4, which contains words occurring between 0.1 and 1 times per million words in modern written English. More about OED's frequency bands
Frequency data is computed programmatically, and should be regarded as an estimate.
Frequency of zero crossing, n., 1940–2010
* Occurrences per million words in written English
Historical frequency series are derived from Google Books Ngrams (version 2), a data set based on the Google Books corpus of several million books printed in English between 1500 and 2010.
The overall frequency for a given word is calculated by summing frequencies for the main form of the word, any plural or inflected forms, and any major spelling variations.
For sets of homographs (distinct entries that share the same word-form, e.g. mole, n.¹, mole, n.², mole, n.³, etc.), we have estimated the frequency of each homograph entry as a fraction of the total Ngrams frequency for the word-form. This may result in inaccuracies.
Smoothing has been applied to series for lower-frequency words, using a moving-average algorithm. This reduces short-term fluctuations, which may be produced by variability in the content of the Google Books corpus.
Decade
Frequency per million words
1940
0.038
1950
0.068
1960
0.11
1970
0.16
1980
0.19
1990
0.21
2000
0.22
2010
0.19
Originally published as part of the entry for zero, n. & adj.