Abstract:
An acoustic treatment apparatus obtains a first output signal by performing filtering for forming a directivity in a first direction for received sound signals of sound receivers, obtains a second output signal by performing filtering for forming a directivity in a second direction different from the first direction for received sound signals of sound receivers, obtains a strength ratio between a strength of the first output signal and a strength of the second output signal, and estimates a sound source direction on the basis of the strength ratio.
Abstract:
An input speech signal to an input terminal is supplied to a speech synthesizer section through a speech analyzer section and frequency parameter quantizer section to form a synthesis filter, and the input speech signal is expressed by quantized LPC coefficients representing the characteristics of the synthesis filter and an excitation signal for exciting the synthesis filter. In this case, in a pulse excitation section, a pulse position selector selects pulse position candidates from the integer pulse positions and non-integer pulse positions stored in a pulse position codebook, and an integer position pulse generator and non-integer position pulse generator respectively generate integer position pulses set at sampling points of the excitation signal and non-integer position pulses set at positions located between sampling points. These pulses are synthesized into a pulse train serving as a source of an excitation signal.
Abstract:
A method for encoding speech wherein an input speech signal is separated by a component separator into a first component mainly constituted by speech and a second component mainly constituted by a background noise at each predetermined unit of time, a bit allocation selector selects bit allocation for each component based on the first and second components from among a plurality of predetermined candidates for bit allocation, a speech encoder and a noise encoder encode the first and second components from the component separator based on the bit allocation according to predetermined different methods for encoding, and a multiplexer multiplexes encoded data of the first and second components and information on the bit allocation and outputs them as transmitted encoded data.
Abstract:
A speech encoding method including generating a reconstruction speech vector by using a code vector extracted from a codebook storing a plurality of code vectors for encoding a speech signal. In addition an input speech signal to be encoded is used as a target vector to generate an error vector representing the error of the reconstruction speech vector with respect to the target vector, and the error vector is passed through a perceptual weighting filter having a transfer function including the inverse characteristics of the transfer function of a filter for emphasizing the spectrum of a reconstructed speech signal. Thus a weighted error vector is generated, the codebook for a code vector that minimizes the weighted error vector is searched, and an index corresponding to the code vector found as an encoding parameter is output.
Abstract:
According to one embodiment, in response to a first acoustic signal output, a second acoustic signal is input. A filter unit is configured to generate a third acoustic signal by convoluting the first acoustic signal with coefficients. A subtraction unit is configured to generate a fourth acoustic signal by subtracting the third acoustic signal from the second acoustic signal. An estimation unit is configured to decide whether a sound volume of the first acoustic signal is below a predetermined threshold, and to set a sound volume of the second acoustic signal as a non-echo sound level when the sound volume of the first acoustic signal is below the predetermined threshold. A determination unit is configured to determine a step size to correct the coefficients using the non-echo sound level. A correction unit is configured to correct the coefficients using the step size.
Abstract:
A speech processing apparatus includes a plurality of microphones which receive speech produced by a first sound source to obtain first speech signals for a plurality of channels having one-to-one correspondence with the plurality of microphones, a calculation unit configured to calculate a first characteristic amount indicative of an inter-channel correlation of the first speech signals, a storage unit configured to store in advance a second characteristic amount indicative of an inter-channel correlation of second speech signals for the plurality of channels obtained by receiving speech produced by a second sound source by the plurality of microphones, and a collation unit configured to collate the first characteristic amount with the second characteristic amount to determine whether the first sound source matches with the second sound source.
Abstract:
A plurality of sound receiving units is installed onto an equipment body. An initial information memory stores an initial direction of the equipment body in a terminal coordinate system based on the equipment body. An orientation detection unit detects an orientation of the equipment body in a world coordinate system based on a real space. A lock information output unit outputs lock information representing to rock the orientation. An orientation information memory stores the orientation detected when the lock information is output. A direction conversion unit converts the initial direction to a target sound direction in the world coordinate system by using the orientation stored in the orientation information memory. A directivity forming unit forms a directivity of the plurality of sound receiving units toward the target sound direction.
Abstract:
A sound signal processing method includes calculating a difference between every few ones of input multiple channel sound signals to obtain a plurality of characteristic quantities each indicating the difference, selecting a weighting factor from a weighting factor dictionary containing a plurality of weighting factors of a plurality of channels corresponding to the characteristic quantities, weighting the sound signals by using the selected weighting factor, and adding the weighted input sound signals to generate an output sound signal.
Abstract:
Adjusting the shape of a spectrum of a speech signal includes the steps of using a first filter with pole-zero transfer function A(z)/B(z) for subjecting a speech signal to a spectrum envelop emphasis and a second filter cascade-connected with the first filter, for compensating for a spectral tilt due to the first filter, independently deriving two filter coefficients used in the second filter for compensating for the spectral tilt from the pole-zero transfer function, and compensating for the spectral tilt corresponding to the pole-zero transfer function according to the derived filter coefficients.
Abstract:
A vector quantizing apparatus includes a first search section for obtaining an approximate vector X1 which is approximated to a desired vector R, a residual vector calculator for calculating a residual vector Rv from the desired vector R and the approximate vector X1, a weighting section for obtaining weighted vectors X2 to XN of code vectors x2 to xN, and a second search section for calculating an estimation value which is the magnitude of a projection vector of the residual vector Rv with respect to the vector space formed by the approximate vector X1 and the weighted vectors X2 to XN, and searching a code vector which maximizes this estimation value.