Patent ID: 11869513
Assignee: VERIDAS DIGITAL AUTHENTICATION SOLUTIONS, S.L.
Field: Computer technology (Electrical engineering)
Classification: CPC G  H | IPC G  H

Claim 19:
20. A method of authenticating a user or speaker, comprising:
obtaining an input speech signal and user credentials identifying the user or speaker, the input speech signal including a single-channel or multi-channel speech signal;
extracting a speech voiceprint from the input speech signal;
retrieving a reference voiceprint associated to the user credentials;
determining a voiceprint correspondence between the speech voiceprint and the reference voiceprint;
authenticating or not authenticating the user or speaker depending on the voiceprint correspondence; and
upon authenticating the user or speaker, using the speech voiceprint used in the authenticating to update the reference voiceprint:
wherein the updating of the reference voiceprint is performed based on the following formula:

et(s)=λ(σ(x),Ψ,γ)et−1(s)+(1−λ(σ(x),Ψ,γ))vt(s′) 

wherein et(s) corresponds to the updated reference voiceprint, et-1(s) corresponds to the reference voiceprint to be updated, vt(s′) corresponds to the speech voiceprint, and λ(σ(χ),ψ, γ) corresponds to a remembering factor balancing a relative importance of et-1(s) and vt(s′) in the updating, optionally said remembering factor λ(σ(χ),ψ, γ) being a truncated monotonic decreasing linear function;
wherein the remembering factor λ(σ(χ),ψ, γ) is determined based on following formula:, λ
      ⁡
      (
      
       
        σ
        ⁡
        (
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       ,
       Ψ
       ,
       γ
      
      )
     
     =
     
      max
      ⁡
      (
      
       
        
         
          
           (
           
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            1
           
           )
          
          ⁢
          
           σ
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           (
           x
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         +
         
          γ
          ⁡
          (
          
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           Ψ
          
          )
         
        
        
         γ
         -
         Ψ
        
       
       ,
       γ
      
      )
     
    
   
   
     
   
  
 

wherein γ is a predefined heuristic factor indicating a minimum importance of et-1(s) during the updating.