Resonance frequency determining method, resonance frequency selecting method, and resonance frequency determining apparatus

A method of detecting a resonant frequency comprising:

• a base step of measuring a base amplitude frequency characteristic;
• a first step of measuring a first amplitude frequency characteristic;
• and
• a second step of measuring a second amplitude frequency characteristic;
• wherein the base amplitude frequency characteristic is an amplitude frequency characteristic obtained by outputting a sound wave of a specified measurement signal from a speaker disposed in a resonant space and by receiving the sound wave in a microphone disposed in the resonant space;
• wherein the first amplitude frequency characteristic is an amplitude frequency characteristic obtained by outputting, from the speaker, a sound wave of the measurement signal and a signal output from the microphone and by receiving the sound wave in the microphone;
• and
• wherein the second amplitude frequency characteristic is an amplitude frequency characteristic obtained by outputting, from the speaker, a sound wave of the measurement signal and a phase-inverted signal obtained by inverting a phase of the signal output from the microphone and by receiving the sound wave in the microphone;
• and
• detecting the resonant frequency in the resonant space based on the base amplitude frequency characteristic, the first amplitude frequency characteristic, and the second amplitude frequency characteristic.

A method of detecting a resonant frequency comprising:

• an attenuation property measuring step of measuring attenuation property of a signal output from a microphone, the microphone being disposed in a resonant space and being configured to receive, from a speaker disposed in the resonant space, a sound wave of a reference frequency signal continued for predetermined time;
• and
• detecting the resonant frequency in the resonant space based on the attenuation property;
• wherein the reference frequency signal is a sine wave signal with a specific frequency or a signal having a component within a predetermined frequency bandwidth including the specific frequency at a center thereof.

A method of detecting a resonant frequency comprising:

• an attenuation property measuring step of measuring attenuation property of a signal output from a microphone, the microphone being disposed in a resonant space and being configured to receive, from a speaker disposed in the resonant space, a sound wave of a reference frequency signal continued for predetermined time and the signal output from the microphone;
• and
• detecting the resonant frequency in the resonant space based on the attenuation property;
• wherein the reference frequency signal is a sine wave signal with a specific frequency or a signal having a component within a predetermined frequency bandwidth including the specific frequency at a center thereof.

A method of detecting a resonant frequency comprising:

• an attenuation property measuring step of measuring attenuation property of a signal output from a microphone, the microphone being disposed in a resonant space and being configured to receive, from a speaker disposed in the resonant space, a sound wave of a reference frequency signal repeated plural times intermittently and a delayed signal obtained by delaying the signal output from the microphone by delay time that is not less than zero;
• and
• detecting the resonant frequency in the resonant space based on the attenuation property;
• wherein the delay time changes to be synchronous with intermittent repeating of the reference frequency signal;
• and
• wherein the reference frequency signal is a sine wave signal with a specific frequency or a signal having a component within a predetermined frequency bandwidth including the specific frequency at a center thereof.

A method of detecting a resonant frequency comprising:

• an attenuation property measuring step of selecting a first sound wave state in which a speaker disposed in a resonant space outputs a sound wave of a reference frequency signal repeated plural times intermittently and a signal output from a microphone disposed in the resonant space, or a second sound wave state in which the speaker outputs a sound wave of the reference frequency signal repeated plural times intermittently and a phase-inverted signal obtained by inverting a phase of the signal output from the microphone, receiving the sound wave in the microphone, and measuring an attenuation property of the signal output from the microphone;
• and
• detecting the resonant frequency in the resonant space based on the attenuation property;
• wherein a sound wave state is changed from the first sound wave state to the second sound wave state or from the second sound wave state to the first sound wave state to be synchronous with intermittent repeating of the reference frequency signal;
• and
• wherein the reference frequency signal is a sine wave signal with a specific frequency or a signal having a component within a predetermined frequency bandwidth including the specific frequency at a center thereof.

An apparatus for detecting a resonant frequency comprising:

• a sound source means;
• a signal switch means;
• and
• a measuring means;
• wherein the sound source means is configured to generate a measurement signal;
• wherein the signal switch means is capable of receiving, as inputs, the measurement signal from the sound source means and a signal output from a microphone;
• wherein the signal switch means is capable of switching its state among a base state in which the measurement signal is output to a speaker so as to cause the speaker to output a sound wave, a first state in which the measurement signal and a first delayed signal obtained by delaying the signal output from the microphone by first delay time that is not less than zero are output to the speaker so as to cause the speaker to output a sound wave, and a second state in which the measurement signal and a second delayed signal obtained by delaying the signal output from the microphone by second delay time that is not less than zero are output to the speaker to cause the speaker to output a sound wave;
• wherein the second delay time is different from the first delay time;
• wherein the measuring means is capable of measuring an amplitude frequency characteristic from the signal output from the microphone;
• and
• wherein the measuring means detects the resonant frequency based on comparison between a base amplitude frequency characteristic obtained by measurement with the state of the signal switch means set to the base state and a first amplitude frequency characteristic obtained by measurement with the state of the signal switch means set to the first state, and comparison between the base amplitude frequency characteristic and a second amplitude frequency characteristic obtained by measurement with the state of the signal switch means set to the second state.

An apparatus for detecting a resonant frequency comprising:

• a sound source means;
• a signal switch means;
• and
• a measuring means;
• wherein the sound source means is configured to generate a measurement signal;
• wherein the signal switch means is capable of receiving, as inputs, the measurement signal from the sound source means and a signal output from a microphone;
• wherein the signal switch means is capable of switching its state among a base state in which the measurement signal is output to a speaker so as to cause the speaker to output a sound wave, a first state in which the measurement signal and the signal output from the microphone are output to the speaker so as to cause the speaker to output a sound wave, and a second state in which the measurement signal and a phase-inverted signal obtained by inverting a phase of the signal output from the microphone are output to the speaker so as to cause the speaker to output a sound wave;
• wherein the measuring means is capable of measuring an amplitude frequency characteristic from the signal output from the microphone;
• and
• wherein the measuring means detects the resonant frequency based on comparison between a base amplitude frequency characteristic obtained by measurement with the state of the signal switch means set to the base state and a first amplitude frequency characteristic obtained by measurement with the state of the signal switch means set to the first state, and comparison between the base amplitude frequency characteristic and a second amplitude frequency characteristic obtained by measurement with the state of the signal switch means set to the second state.

An apparatus for detecting a resonant frequency comprising:

• a sound source means;
• and
• a measuring means;
• wherein the sound source means is capable of generating and outputting a measurement signal;
• wherein the measurement signal is a reference frequency signal continued for a predetermined time;
• wherein the reference frequency signal is a sine wave signal with a specific frequency or a signal having a component within a predetermined frequency bandwidth including the specific frequency at a center thereof;
• wherein the measuring means is capable of receiving as an input the signal output from the microphone;
• and
• wherein the measuring means measures an attenuation property of the signal output from the microphone and detects the resonant frequency based on the attenuation property.

An apparatus for detecting a resonant frequency comprising:

• a sound source means;
• a signal output means;
• and
• a measuring means;
• wherein the sound source means is configured to generate a measurement signal;
• wherein the measurement signal is a reference frequency signal continued for a predetermined time;
• wherein the reference frequency signal is a sine wave signal with a specific frequency or a signal having a component within a predetermined frequency bandwidth including the specific frequency at a center thereof;
• wherein the signal output means is capable of receiving as inputs the measurement signal from the sound source means and the signal output from the microphone;
• wherein the signal output means is capable of outputting, to a speaker, the measurement signal and the signal output from the microphone so as to cause the speaker to output a sound wave;
• wherein the measuring means is capable of receiving as an input the signal output from the microphone;
• and
• wherein the measuring means measures an attenuation property of the signal output from the microphone and detects the resonant frequency based on the attenuation property.

An apparatus for detecting a resonant frequency comprising:

• a sound source means;
• a signal output means;
• and
• a measuring means;
• wherein the sound source means is configured to generate a measurement signal;
• wherein the measurement signal is a reference frequency signal repeated plural times intermittently;
• wherein the reference frequency signal is a sine wave signal with a specific frequency or a signal having a component within a predetermined frequency bandwidth including the specific frequency at a center thereof;
• wherein the signal output means is capable of receiving as inputs the measurement signal from the sound source means and the signal output from the microphone;
• wherein the signal output means is capable of outputting, to a speaker, the measurement signal and a delayed signal obtained by delaying the signal output from the microphone by delay time that is not less than zero so as to cause the speaker to output a sound wave;
• wherein signal output means changes the delay time to be synchronous with intermittent repeating of the reference frequency signal;
• wherein the measuring means is capable of receiving as an input the signal output from the microphone;
• and
• wherein the measuring means measures an attenuation property of the signal output from the microphone and detects the resonant frequency based on the attenuation property.

An apparatus for detecting a resonant frequency comprising:

• a sound source means;
• a signal output means;
• and
• a measuring means;
• wherein the sound source means is con figured to generate a measurement signal;
• wherein the measurement signal is a reference frequency signal repeated plural times intermittently;
• wherein the reference frequency signal is a sine wave signal with a specific frequency or a signal having a component within a predetermined frequency bandwidth including the specific frequency at a center thereof;
• wherein the signal output means is capable of receiving as inputs the measurement signal from the sound source means and the signal output from the microphone;
• wherein the signal output means is selectively setting its state to a first output state in which the signal output means outputs, to a speaker, the measurement signal and the signal output from the microphone so as to cause the speaker to output a sound wave, or to a second output state in which the signal output means outputs, to the speaker, the measurement signal and a phase-inverted signal obtained by inverting a phase of the signal output from the microphone so as to cause the speaker to output a sound wave;
• wherein the signal output means changes its state from the first output state to the second output state or from the second output state to the first output state so as to be synchronous with intermittent repeating of the reference frequency signal;
• wherein the measuring means is capable of receiving as an input the signal output from the microphone;
• and
• wherein the measuring means measures attenuation property of the signal output from the microphone and detects the resonant frequency based on the attenuation property.