Abstract: A voice sample characterization front-end suitable for use in a distributed speech recognition context. A digitized voice sample 31 is split between a low frequency path 32 and a high frequency path 33. Both paths are used to determine spectral content suitable for use when determining speech recognition parameters (such as cepstral coefficients) that characterize the speech sample for recognition purposes. The low frequency path 32 has a thorough noise reduction capability. In one embodiment, the results of this noise reduction are used by the high frequency path 33 to aid in de-noising without requiring the same level of resource capacity as used by the low frequency path 32.

Abstract: A voice sample characterization front-end suitable for use in a distributed speech recognition context. A digitized voice sample 31 is split between a low frequency path 32 and a high frequency path 33. Both paths are used to determine spectral content suitable for use when determining speech recognition parameters (such as cepstral coefficients) that characterize the speech sample for recognition purposes. The low frequency path 32 has a thorough noise reduction capability. In one embodiment, the results of this noise reduction are used by the high frequency path 33 to aid in de-noising without requiring the same level of resource capacity as used by the low frequency path 32.

Abstract: A system for enhancing the signal-to-noise ratio of a speech signal is avoided. A plurality of local energy maximums associated with a speech signal are determined. Presumably, each of these local energy maximums defines a speech pitch period. Typically, human pitch periods are approximately 100-400 Hz depending on the sex and age of the speaker. Because human speech typically includes more energy near the beginning of a pitch period than at the end of the pitch period, and background noise tends to remain relatively constant throughout the pitch period, the speech signal may be enhanced by increasing the energy associated with the beginning of the pitch period and/or by decreasing the energy associated with the end of the pitch period. Preferably, the amount of energy increase in the earlier portion of the pitch period is approximately equal to the amount of energy reduction in the later portion of the pitch period. In this manner, the total energy remains the constant.

Abstract: A system for enhancing the signal-to-noise ratio of a speech signal is disclosed. A plurality of local energy maximums associated with a speech signal are determined. Presumably, each of these local energy maximums defines a speech pitch period. Typically, human pitch periods are approximately 100-400 Hz depending on the sex and age of the speaker. Because human speech typically includes more energy near the beginning of a pitch period than at the end of the pitch period, and background noise tends to remain relatively constant throughout the pitch period, the speech signal may be enhanced by increasing the energy associated with the beginning of the pitch period and/or by decreasing the energy associated with the end of the pitch period. Preferably, the amount of energy increase in the earlier portion of the pitch period is approximately equal to the amount of energy reduction in the later portion of the pitch period. In this manner, the total energy remains the constant.