Abstract: A sound field measuring apparatus has: an exponential pulse generator 11 which outputs a pulse signal to speakers 4a, 4b, . . . ; a microphone 6 which is disposed in an acoustic space 5 where the speakers 4a, 4b, . . . are disposed, and which detects a pulse signal output from each of the speakers 4a, 4b, . . . ; and a calculation section 15 which detects a time when the signal detected by the microphone 6 exceeds a predetermined threshold. The calculation section 15 calculates a time period from a time when the pulse signal is generated by the exponential pulse generator 11 to the time when the signal exceeds the predetermined threshold.

Abstract: A signal of a whole audio frequency band is input to input lines CHL and CHR having band-split digital band pass filters BFL1 to BFLn and BFR1 to BFRn, attenuators ATL1 to ATLn and ATR1 to ATRn, delay elements ZL1 to ZLn and ZR1 to ZRn, and adders 21 to 24, thereby causing speakers 25 and 26 to generate sounds. The reproduced sounds are picked up by microphones 27 and 28 placed at listening positions. The obtained pick-up signals PR and PL are passed through band-split digital band pass filters BFL1′ to BFLn′ and BFR1′ to BFRn′ which are set to the same bands as those of the band-split digital band pass filters BFL1 to BFRn, to generate test data DL1(t) to DLn(t) and DR1(t) to DRn(t). On a basis of the test data, an interaural correlation coefficient &rgr;RL is calculated.

Abstract: In correcting the sound field, the loudspeakers 6FL to 6WF are sounded by the noise. The attenuation factors of the inter-band attenuators ATF11 to ATFki for adjusting gains of the band-pass filters BPF11 to BPFki to the frequency in respective channels are corrected based on detection results of the reproduced sounds of the loudspeakers 6FL to 6WF. Then, the attenuation factors of the channel-to-channel attenuators ATG1 to ATG5 are corrected based on the detection results of the reproduced sounds of the loudspeakers 6FL to 6WF. Then, the delay times of the delay circuits DLY1 to DLY5 are corrected based on the detection results of the reproduced sounds of the loudspeakers 6FL to 6WF. Then, the attenuation factor of the channel-to-channel attenuator ATGk is corrected based on the detection result of the reproduced sound of the loudspeaker 6WF as the subwoofer, whereby the levels of the reproduced sounds reproduced by the loudspeakers 6FL to 6WF are adjusted to be made flat over the audio frequency band.

Abstract: In correcting the sound field, the loudspeakers 6FL to 6WF are sounded by the noise. The attenuation factors of the inter-band attenuators ATF11 to ATFki for adjusting gains of the band-pass filters BPF11 to BPFki to the frequency in respective channels are corrected based on detection results of the reproduced sounds of the loudspeakers 6FL to 6WF. Then, the attenuation factors of the channel-to-channel attenuators ATG1 to ATG5 are corrected based on the detection results of the reproduced sounds of the loudspeakers 6FL to 6WF. Then, the delay times of the delay circuits DLY1 to DLY5 are corrected based on the detection results of the reproduced sounds of the loudspeakers 6FL to 6WF. Then, the attenuation factor of the channel-to-channel attenuator ATGk is corrected based on the detection result of the reproduced sound of the loudspeaker 6WF as the subwoofer, whereby the levels of the reproduced sounds reproduced by the loudspeakers 6FL to 6WF are adjusted to be made flat over the audio frequency band.

Abstract: A filter coefficient of a graphic equalizer GEQ is corrected based on detection results of reproduced sounds generated by supplying a noise to all frequency band loudspeakers 6FL to 6RR and a low frequency band exclusively reproducing loudspeaker 6WF via the graphic equalizer GEQ. Then, attenuation factors of channel-to-channel attenuators ATG1 to ATG5 are corrected based on the detection results of the reproduced sounds generated by supplying the noise to the loudspeakers 6FL to 6RR via the graphic equalizer. Then, delay times of delay circuits DLY1 to DLYk are corrected based on the detection results of the reproduced sounds generated by supplying the noise to the loudspeakers 6FL to 6WF via the graphic equalizer.

Abstract: In correcting the sound field, loudspeakers 6FL to 6WF are sounded by the noise. The attenuation factors of the inter-band attenuators ATF11to ATFki for adjusting gains of the band-pass filters BPF11to BPFki to the frequency in respective channels are corrected based on detection results of the reproduced sounds of the loudspeakers 6FL to 6WF. The attenuation factors of channel-to-channel attenuators ATG1 to ATG5 are corrected based on the detection results of the reproduced sounds of the loudspeakers 6FL to 6WF. The delay times of delay circuits DLY1 to DLY5 are corrected based on the detection results of the reproduced sounds of the loudspeakers 6FL to 6WF. The attenuation factor of a channel-to-channel attenuator ATGk is corrected based on the detection result of the reproduced sound of the loudspeaker 6WF as the subwoofer. Therefore, the levels of the reproduced sounds reproduced by the loudspeakers 6FL to 6WF are adjusted to be made flat over the audio frequency band.

Abstract: A speaker system for use in an automobile vehicle, comprises: a pair of front speakers for converting electric signals fed from a two-channel source into sound signals; a band pass filter for extracting a signal component having a frequency substantially satisfying .lambda.=2L when the automobile vehicle has a length L; a phase adjusting circuit for adjusting the phase of an electric signal; and a rear speaker for converting an electric signal fed through the phase adjusting circuit and the band pass filter into a sound signal.

Abstract: A speaker system for use in an automobile vehicle, comprises: pair of side speakers disposed on left and right sides in a front section within the automobile vehicle; a central speaker disposed in a middle position between the two side speakers; a pair of delay circuits connected on two signal lines leading to the side speakers disposed on the left and right sides within the vehicle; an adder connected between the left and right channels to add together the electric signals transmitted from the left and right channels so as to produce a sum signal; and a band pass filter connected on a signal line leading to the central speaker, said band pass filter being constructed and adjusted to eliminate a high frequency signal component. The sum signal fed from the adder is passed through the band pass filter before being applied to the central speaker.

Abstract: A flush toilet stool includes a toilet bowl and a trap drainage passage connected to the toilet bowl. The toilet bowl has a water jet hole defined in a bottom region thereof and opening toward the trap drainage passage. A pressurizing unit such as a water pump is coupled to the water jet hole for drawing water under lower pressure directly from an external water supply and expelling the water under higher pressure through the water jet hole toward the trap drainage passage to develop a siphon flow to discharge sewage from the toilet bowl through the trap drainage passage.

Abstract: A bubbly water outlet device comprises a swirl chamber which is connected to a water supply source and is adapted to swirl a flow, and a bubbler chamber which is connected to the swirl chamber through a discharge port provided substantially at a center of the swirl chamber. The bubbler chamber is adapted to suck air from an exterior by virtue of the inflow of water from the discharge port and is capable of discharging bubbly water.