摘要:
A sound field controller for generating apparent sound sources by adjusting the amplitude and delay time of a sound signal so that the sound will be perceived by plural listeners as sound coming from a location separated from the specific location of the front speakers, and for additionally controlling the effect of the apparent sound sources by evaluating the attributes of the source sound signal. The controller includes FIR filters for generating a left sound pattern signal, FIR filters for generating a right sound pattern signal, a first delay circuit for delaying the left and right sound pattern signals by a first predetermined time and applying the delayed left and right sound pattern signals to the left and right speakers, respectively, to introduce an apparent sound source located left rear of a center listener; and a second delay circuit for delaying the left and right sound pattern signals by a second predetermined time and applying the delayed left and right sound pattern signals to the right and left speakers, respectively, to introduce an apparent sound source located right rear of a center listener.
摘要:
A sound reproduction system for automatically conducting a tone control for an audio signal according to the present invention includes: an input terminal for inputting an audio signal; a judgment circuit for determining a ratio between a stereophonic signal component and a monophonic signal component of the input audio signal and for outputting a judgment signal; a signal processing section for receiving the input audio signal and processing the input audio signal so as to generate an output signal having uniform transmission characteristics irrespective of the listening position; an adder for receiving the input audio signal and the output signal and for adding the input audio signal with the output signal at a certain addition ratio based on the judgment signal so as to generate an added signal; and a loudspeaker for receiving the added signal and for reproducing the added signal in a plurality of positions.
摘要:
The apparatus of the invention calculates filter coefficients for controlling sound field and sound image, based on a plurality of first impulse response signals and a pair of second impulse response signals. The plurality of first impulse response signals indicate impulse responses from loudspeakers reproducing audio signals to both ears of a listener. The pair of second impulse response signals indicate impulse responses from a reference loudspeaker at a position at which a sound image is localized to both ears of the listener. The apparatus includes: a feature extracting section for receiving the pair of second impulse response signals, for extracting parameters representing features of the pair of second impulse response signals, and for outputting parameter signals; a signal adjusting section for adjusting at least one of the plurality of first impulse response signals based on the parameter signals, and for outputting a pair of third impulse response signals having the same features as the extracted features; and a coefficient calculating section for calculating the filter coefficients for controlling the sound field and sound image, based on the plurality of first impulse response signals and the pair of third impulse response signals applied from the signal adjusting means.
摘要:
The apparatus of the invention calculates filter coefficients for controlling sound field and sound image, based on a plurality of first impulse response signals and a pair of second impulse response signals. The plurality of first impulse response signals indicate impulse responses from loudspeakers reproducing audio signals to both ears of a listener. The pair of second impulse response signals indicate impulse responses from a reference loudspeaker at a position at which a sound image is localized to both ears of the listener. The apparatus includes: a feature extracting section for receiving the pair of second impulse response signals, for extracting parameters representing features of the pair of second impulse response signals, and for outputting parameter signals; a signal adjusting section for adjusting at least one of the plurality of first impulse response signals based on the parameter signals, and for outputting a pair of third impulse response signals having the same features as the extracted features; and a coefficient calculating section for calculating the filter coefficients for controlling the sound field and sound image, based on the plurality of first impulse response signals and the pair of third impulse response signals applied from the signal adjusting means.
摘要:
A sound signal picked-up by a microphone is processed in a howl suppresser including a digital filter. A frequency analyzer performs frequency analysis of the picked-up sound signal. A howl detector detects a howl contained in the sound signal from a result of frequency analysis by the frequency analyzer. A coefficient calculator calculates coefficients to be input to the digital filter to suppress the howl according to a detection result by the howl detector, and a controller inputs the calculated coefficients to the digital filter. The howl detector judges that a maximum peak power level among power levels of the sound signal in a frequency region analyzed by the frequency analyzer is a howl component when a ratio of the maximum peak power level to a mean power level of the sound signal is larger than a predetermined threshold level, preferably for a predetermined threshold time. Also, a threshold controller is provided for controlling the threshold level and/or the threshold time so as to enhance the accuracy of the howl detection.
摘要:
A music/voice discriminating apparatus is composed of a signal processing portion for effecting the signal processing upon input acoustic signals, a music/voice deciding portion for discriminating whether the input acoustic signals are music or voice, a first signal processing portion for optimally setting acoustic parameters for the signal processing respectively for music or voice, and a second signal processing portion for controlling the acoustic parameters of the first signal processing portion in accordance with the decision results of the music/voice deciding portion so that it may become a desirable value set in the second parameter setting portion.
摘要:
A sound field is generated responsive to direct sound picked up by a direct-sound collecting microphone and indirect-sound picked up by an indirect-sound collecting microphone. Respective processing circuits are provided for signal processing the sound signals of the direct-sound collecting microphone and the indirect-sound collecting microphone. An adaptive filter is provided having a transfer function equal to a transfer function from a reproducing speaker to the indirect-sound collecting microphone. The output of the signal processing circuit associated with the indirect-sound collecting microphone is filtered by the adaptive filter, and the output of the adaptive filter is subtracted from the output of the indirect-sound collecting microphone. The output of the subtractor is then applied to the signal processing circuit associated with the indirect-sound collecting microphone for signal processing. The transfer function is initially set in the adaptive filter by applying an output of a signal generator thereto.
摘要:
Control codes for controlling processing of an audio signal by a sound field variation circuit to produce desired sound fields are recorded on a monaural track of a video tape concurrent with recording of video and audio signals, and can thereby be subsequently played back for producing sound fields which are respectively synchronized with video images.
摘要:
A reflection sound compression apparatus extracts and compresses, most appropriately with a physical evaluation value, an impulse response of a hall, etc. which is obtained by calculation and actual experiments to reflection sounds in a number required by a sound field controller by using a learning identification method.
摘要:
A sound field switcher inputs an output sound field signal from a sound field producer. The inputted sound field signal is delayed sequentially by plural delayers, after which they are multiplied by coefficients by plural multipliers, and the multiplied results are all added by an adder. Coefficients stored in an area of a memory indicated by a coefficient counter are read out and set to the plural multipliers. The sound field switcher carries out control of the timing for switching the sound field signal produced by the sound field producer and the timing for the coefficient counter to commence counting. Assuming the time required for switching the sound field to be N sampling periods, in case of carrying out a sound field switching from a sound field A to a sound field B, a sound field switching controller issues an order to the coefficient counter so as to count up one by one from 0 to N, and on each count the coefficients stored in an area of the coefficient memory is set to the multipliers. When the count value of the coefficient counter comes to (N/2) or nearest to (N/2), the sound field switching controller issues an order to the sound field producer to output the sound field signal of the sound field B. When the count value of the coefficient counter comes to N, the switching from the sound field A to the sound field B is completed.