Pitch candidate selection method for multi-channel pitch detectors
First Claim
1. A method for estimating the pitch of a signal comprising:
- determining multiple pitch candidates from said signal. determining multiple signal features (i.e. a feature vector) for each of the pitch candidates. estimating the parameters of a likelihood function on the feature space which returns the likelihood that a pitch candidate is correct based on the position of its corresponding feature vector. determining the likelihood that each pitch candidate is correct by evaluating the likelihood function at the position defined by each of the said pitch candidate'"'"'s feature vectors. determining the output pitch to be a function of the individual pitch candidates and their likelihood of being correct.
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Abstract
An improved method of performing channel selection in multi-channel pitch detection systems. For each channel, several features are computed using the input signal and the value of the pitch candidate from the channel. The resulting feature vector is used to evaluate a multi-variate likelihood function which defines the likelihood that the pitch candidate represents the correct pitch. The final pitch estimate is then taken to be the pitch candidate with the highest likelihood of being correct, or the mean (or median) of the pitch candidates with likelihoods above a given threshold. The functional form of the likelihood function can be defined using several different parametric representations, and the parameters of the likelihood function can be advantageously derived in an automated manner using signals having pitch labels that are considered to be correct. This represents a significant improvement over previous channel selection methods where the parameters are chosen laboriously by hand.
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Citations
25 Claims
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1. A method for estimating the pitch of a signal comprising:
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determining multiple pitch candidates from said signal. determining multiple signal features (i.e. a feature vector) for each of the pitch candidates. estimating the parameters of a likelihood function on the feature space which returns the likelihood that a pitch candidate is correct based on the position of its corresponding feature vector. determining the likelihood that each pitch candidate is correct by evaluating the likelihood function at the position defined by each of the said pitch candidate'"'"'s feature vectors. determining the output pitch to be a function of the individual pitch candidates and their likelihood of being correct. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25)
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14. The method of 13, where the parameters of the Gaussian functions in the model are determined completely from the data.
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15. The method of 13, where the pdƒ
- of the correct class is modelled as a single Gaussian, and the pdƒ
of the incorrect class is modelled as the sum of three or more Gaussians representing pitch candidates corresponding to 1/2 the correct pitch, 2 times the correct pitch, possibly higher or lower integer multiples, and a catch all class for pitch candidates that correspond to an incorrect pitch but do not fall into one of the pre-defined categories.
- of the correct class is modelled as a single Gaussian, and the pdƒ
Specification