Abstract: To realize sound output so that a listener does not feel unnaturalness, an audio signal for a center speaker is multiplied by a transfer function for a left speaker and a transfer function for a right speaker, respectively, and an audio component for a left center speaker and an audio component for a right center speaker that correspond to a listening point are generated. An audio signal for the left speaker and an audio signal for the right speaker are synthesized with the audio component for the left center speaker and the audio component for the right center speaker, respectively. Thereby, a sound image can be oriented as if a sound based on the audio signal for the center speaker is emitted from a position at which a center speaker would be set if the system had a center speaker.

Abstract: A frequency-characteristic-acquisition device that inputs a time-stretched-pulse signal to a system to be measured and that acquires information about a frequency characteristic of the system on the basis of a signal output from the system is provided. The frequency-characteristic-acquisition device includes a control unit which performs control so that the time-stretched-pulse signal is expanded in a time-axis direction and output to the system, and an acquisition unit that analyzes the signal output from the system and that acquires the frequency-characteristic information.

Abstract: A sound measuring apparatus for measuring a sound-arrival delay time from a speaker to a microphone on the basis of a result obtained by outputting a test signal from the speaker and picking up the test signal using the microphone includes the following elements. A control unit performs control so that the test signal is expanded in a time axis and is then output from the speaker. A delay time measuring unit measures an expansion-based measured delay time on the basis of a delay time that is measured on the basis of a time difference between the test signal expanded in the time axis and output from the speaker and a signal obtained from the microphone by picking up the output expanded test signal, and obtains the sound-arrival delay time as the expansion-based measured delay time.

Abstract: A measuring apparatus that measures sound arrival delay time from a speaker to a microphone on the basis of a result obtained by collecting signals output from the speaker by means of the microphone includes: measuring means for measuring the sound arrival delay time that makes a control such that a first sine wave signal having a first frequency and a second sine wave signal having a second frequency different from the first frequency are output from the speaker, is input with the first sine wave signal and the second sine wave signal collected by the microphone and then mixes the first sine wave signal and the second sine wave signal so as to generate a third sine wave signal having a frequency corresponding to a difference between the first frequency and the second frequency, and measures the sound arrival delay time on the basis of the third sine wave signal.

Abstract: The sound field compensating apparatus includes a section that generates sound-volume regulating test signal; a driving section that drives a speaker; a microphone that receives the output from the speaker; and a control section that processes an output signal of the microphone and that controls operations of respective sections. The sound-volume regulating test signal is a sum signal representative of the sum of single-frequency sinusoidal wave signals whose frequencies are set to the relationship of an integer ratio. The control section causes the driving section to drive the speaker by using the sound-volume regulating test signal to thereby detect signal levels of frequency components of the sinusoidal wave signals from output signals of the microphone. In accordance with an average value of the signal levels, the control section sets a measuring sound volume when the speaker is driven by using the measuring test signal.

Abstract: A sound field measurement apparatus includes a signal generating unit for outputting a burst signal, a driving unit for driving a speaker using the burst signal, a microphone for picking up an audio output from the speaker, an analog-digital converter for performing analog-digital conversion processing on an output signal from the microphone and outputting picked-up audio data, a filtering unit for performing filtering processing on the picked-up audio data, and an analyzing unit for determining a propagation time of the audio output from the speaker to the microphone in accordance with data output from the filtering unit. In this sound field measuring apparatus, the filtering unit is an IIR filter configured to filter the picked-up audio data forward and then backward along a time axis, or an IIR filter configured to filter the picked-up audio data backward and then forward along the time axis.