Verification score normalization in a speaker voice recognition device
First Claim
1. - a device for automatically recognizing the voice of a speaker authorized to access an application, said device comprising means for generating beforehand, during a learning phase, parameters of an acceptance voice model relative to a voice segment spoken by said authorized speaker and parameters of a rejection voice model, means for normalizing by means of normalization parameters a speaker verification score depending on the likelihood ratio between a voice segment to be tested and said acceptance model and rejection model thereby driving a normalized verification score, and means for comparing said normalized verification score to a first threshold in order to authorize access to the application by the speaker who spoke said voice segment to be tested only if the normalized verification score is at least as high as the first threshold, and means for updating at least one of said normalization parameters as a function of a preceding value of said one normalization parameter and the speaker verification score on each voice segment test only if the normalized verification score is at least equal to a second threshold that is at least equal to said first threshold.
1 Assignment
0 Petitions
Accused Products
Abstract
During a learning phase, a speech recognition device generates parameters of an acceptance voice model relating to a voice segment spoken by an authorized speaker and a rejection voice model. It uses normalization parameters to normalize a speaker verification score depending on the likelihood ratio of a voice segment to be tested and the acceptance model and rejection model. The speaker obtains access to a service application only if the normalized score is above a threshold. According to the invention, a module updates the normalization parameters as a function of the verification score on each voice segment test only if the normalized score is above a second threshold.
60 Citations
10 Claims
- 1. - a device for automatically recognizing the voice of a speaker authorized to access an application, said device comprising means for generating beforehand, during a learning phase, parameters of an acceptance voice model relative to a voice segment spoken by said authorized speaker and parameters of a rejection voice model, means for normalizing by means of normalization parameters a speaker verification score depending on the likelihood ratio between a voice segment to be tested and said acceptance model and rejection model thereby driving a normalized verification score, and means for comparing said normalized verification score to a first threshold in order to authorize access to the application by the speaker who spoke said voice segment to be tested only if the normalized verification score is at least as high as the first threshold, and means for updating at least one of said normalization parameters as a function of a preceding value of said one normalization parameter and the speaker verification score on each voice segment test only if the normalized verification score is at least equal to a second threshold that is at least equal to said first threshold.
Specification