Method and system for coding human speech for subsequent reproduction thereof

• US 6,044,345 A
• Filed: 04/17/1998
• Issued: 03/28/2000
• Est. Priority Date: 04/18/1997
• Status: Expired due to Fees

• Current Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Original Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Inventors: Veldhuis, Raymond N. J.
• Primary Examiner(s): Dorvil, Richemond
• Application Number:
  US09/062,224
• Time in Patent Office: 711 Days
• Field of Search: 704/261, 704/260, 704/268, 704/200, 704/207, 704/209, 704/201, 704/211, 704/262, 704/219
• US Class Current: 704/261
• CPC Class Codes: G10L 19/06 Determination or coding of the spectral characteristics, e.g. of the short-term prediction coefficients

Abstract

Human speech is coded by singling out from a transfer function of the speech, all poles that are unrelated to any particular resonance of a human vocal tract model. All other poles are maintained. A glottal pulse related sequence is defined representing the singled out poles through an explicitation of the derivative of the glottal air flow. Speech is outputted by a filter based on combining the glottal pulse related sequence and a representation of a formant filter with a complex transfer function expressing all other poles. The glottal pulse sequence is modelled through further explicitly expressible generation parameters. In particular, a non-zero decaying return phase supplemented to the glottal-pulse response that is explicitized in all its parameters, while amending the overall response in accordance with volumetric continuity.

Claims

1. A method for coding human speech for subsequent reproduction thereof, said method comprising the steps of:

receiving an amount of human-speech-expressive information;

defining a transfer function of said speech and singling out therefrom all poles that are unrelated to any particular resonance of a human vocal tract model, while maintaining all other poles;

defining a glottal pulse related sequence representing said singled out poles through an explicitation of the derivative of the glottal air flow;

outputting speech represented by filter means based on combining said glottal pulse related sequence and a representation of a formant filter with a complex transfer function as expressing said all other poles,

wherein said glottal pulse sequence is modelled through further explicitly expressible generation parameters,

said method being characterized by supplementing a non-zero decaying return phase to the glottal-pulse response that is explicitized in all its parameters, whilst amending the overall response in accordance with volumetric continuity.

2. A method as claimed in claim 1, being characterized by in said glottal pulse response introducing a factor that is explicit in the parameter t_p, that is the instant of maximum airflow.

3. A method as claimed in claim 2, being characterized by selectively amending one or more of the speech governing parameters t_p, t_e, that is the instant where the derivative in the glottal pulse is minimum, and t_a, that is the first order delay after t_e where the derivative becomes zero.

4. A system arranged for implementing a method as claimed in claim 1.