Method and apparatus for determining the direction of a sound source
First Claim
1. A signal processing method comprising:
- an input step of entering an audio signal including a periodic audio signal with a predetermined period;
a level detecting step of detecting the level of the audio signal entered at said input step and generating a level signal;
a period detecting step of detecting a period of the audio signal entered at said input step; and
a selecting step of selecting corresponding image pick-up means and inputting an image to said selected pick-up means if the level signal is greater than a prescribed threshold value, the period detected at said period detecting step falls within a prescribed range,wherein said selecting step selects the corresponding image pick-up means and inputs the image to said selected pick-up means if the level signal is greater than the prescribed threshold value, a centroid of autocorrelation values corresponding to respective periods detected at said period detecting step within a time duration T falls within a prescribed centroid range and an autocorrelation value corresponding to said centroid is greater than a prescribed threshold value.
1 Assignment
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Accused Products
Abstract
FIG. 1 illustrates the construction of an audio signal processor according to the present invention. An audio signal enters from a microphone 1 and a bandpass filter 2 extracts the frequency band of the human voice. The resulting signal is amplified by an amplifier 3. A level detecting circuit 4 detects the level of the amplified signal. A level discriminating circuit 5 determines if the level is greater than the value. If yes, the circuit 5 outputs a switch-on signal. Or else, the circuit 5 outputs a switch-off signal. An A/D converter 6 converts the analog signal entering from the circuit 5 into a digital signal. A pitch detecting circuit 7 detects the pitch of the digital signal. A pitch discriminating circuit 8 determines if the pitch of the signal agrees with a prescribed pitch. If yes, the circuit 8 outputs the switch-on signal to the voice-output control switch 13. On the basis of the switch-on or switch-off signal, the switch 13 generates an on/off control signal, which causes a voltage-controlled amplifier 9 to amplify and output the voice signal and output to a mixer 10. Voice processing circuits S and S'"'"' are identical in construction. Microphones 1, 1'"'"' of the processing circuits S, S'"'"' are connected to a mixer 10. The latter mixes the audio outputted by the microphones 1, 1'"'"'. An amplifier 11 amplifies the mixed voice signals. A speaker 12 outputs the audio.
26 Citations
20 Claims
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1. A signal processing method comprising:
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an input step of entering an audio signal including a periodic audio signal with a predetermined period; a level detecting step of detecting the level of the audio signal entered at said input step and generating a level signal; a period detecting step of detecting a period of the audio signal entered at said input step; and a selecting step of selecting corresponding image pick-up means and inputting an image to said selected pick-up means if the level signal is greater than a prescribed threshold value, the period detected at said period detecting step falls within a prescribed range, wherein said selecting step selects the corresponding image pick-up means and inputs the image to said selected pick-up means if the level signal is greater than the prescribed threshold value, a centroid of autocorrelation values corresponding to respective periods detected at said period detecting step within a time duration T falls within a prescribed centroid range and an autocorrelation value corresponding to said centroid is greater than a prescribed threshold value. - View Dependent Claims (2)
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3. A signal processing method comprising:
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an input step of entering an audio signal including a periodic audio signal with a predetermined period; a level detecting step of detecting the level of the audio signal entered at said input step and generating a level signal; a period detecting step of detecting a period of the audio signal entered at said input step; and a selecting step of selecting corresponding image pick-up means and inputting an image to said selected pick-up means if the level signal is greater than a prescribed threshold value, the period detected at said period detecting step falls within a prescribed range, wherein said period detecting step includes; a step of partitioning the audio signal entered at said input step into audio signals each of a time duration T; a step of further partitioning each of the partitioned audio signals into audio signals each of a time duration t; and a frame period detecting step of detecting periodicity of the audio signals of time duration t. - View Dependent Claims (4, 5)
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6. A signal processing method comprising:
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an input step of entering an audio signal including a periodic audio signal with a predetermined period; a level detecting step of detecting the level of the audio signal entered at said input step and generating a level signal; a period detecting step of detecting a period of the audio signal entered at said input step; and an audio control output step of outputting a sound corresponding to the audio signal entered at said input step if the level signal is greater than a prescribed threshold value and the period detected at said period detecting step falls within a prescribed range, wherein said selecting step outputs a sound corresponding to the audio signal entered at said input step if the level signal is greater than the prescribed threshold value, a centroid of autocorrelation values corresponding to respective periods detected at said period detecting step within a time duration T falls within a prescribed centroid range and an auto correlation value corresponding to said centroid is greater than a prescribed threshold value. - View Dependent Claims (7)
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8. A signal processing method comprising:
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an input step of entering an audio signal including a periodic audio signal with a predetermined period; a level detecting step of detecting the level of the audio signal entered at said input step and generating a level signal; a period detecting step of detecting a period of the audio signal entered at said input step; and an audio control output step of outputting a sound corresponding to the audio signal entered at said input step if the level signal is greater than a prescribed threshold value and the period detected at said period detecting step falls within a prescribed range, wherein said period detecting step includes; a step of partitioning the audio signal entered at said input step into audio signals each of a time duration T; a step of further partitioning each of the partitioned audio signals into audio signals each of a time duration t; and a frame period detecting step of detecting periodicity of the audio signals of time duration t. - View Dependent Claims (9, 10)
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11. A signal processing apparatus comprising:
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input means for entering an audio signal including a periodic audio signal with a predetermined period; level detecting means for detecting a level of the audio signal entered by said input means and generating a level signal; period detecting means for detecting a period of the audio signal entered by said input means; and selecting means for selecting corresponding image pick-up means and inputting an image to said selected pick-up means if the level signal is greater than a prescribed threshold value and the period detected by said period detecting means falls within a prescribed range, wherein said selecting means selects the corresponding image pick-up means and inputs the image to said selected pick-up means if the level signal is greater than the prescribed threshold value, a centroid of autocorrelation values corresponding to respective periods detected by said period detecting means within a time duration T falls within a prescribed centroid range and an autocorrelation value corresponding to said centroid is greater than a prescribed threshold value. - View Dependent Claims (12, 13)
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14. A signal processing apparatus comprising:
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input means for entering an audio signal including a periodic audio signal with a predetermined period; level detecting means for detecting a level of an audio signal entered by input means and generating a level signal; period detecting means for detecting a period of the audio signal entered by said input means; and selecting means for selecting corresponding image pick-up means and inputting an image to said selected pick-up means if the level signal is greater than a prescribed threshold value and the period detected by said period detecting means falls within a prescribed range, wherein said period detecting means includes; means for partitioning the audio signal entered by said input means into audio signals each of a time duration T; means for further partitioning each of the partitioned audio signals into audio signals each of a time duration t; and frame period detecting means for detecting periodicity of the audio signals of time duration t. - View Dependent Claims (15)
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16. A signal processing apparatus comprising:
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input means for entering an audio signal including a periodic audio signal with a predetermined period; level detecting means for detecting a level of the audio signal entered by said input means and generating a level signal; period detecting means for detecting a period of the audio signal entered by said input means; and audio control output means for outputting a sound corresponding to the audio signal entered by said input means if the level signal is greater than a prescribed threshold value and the period detected by said period detecting means falls within a prescribed range, wherein said selecting means outputs a sound corresponding to the audio signal entered by said input means if the level signal is greater than the prescribed threshold value, a centroid of autocorrelation values corresponding to respective periods detected by said period detecting means within a time duration T falls within a prescribed centroid range and an autocorrelation value corresponding to said centroid is greater than a prescribed threshold value. - View Dependent Claims (17)
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18. A signal processing apparatus comprising:
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input means for entering an audio signal including a periodic audio signal with a predetermined period; level detecting means for detecting a level of the audio signal entered by said input means and generating a level signal; period detecting means for detecting a period of the audio signal entered by said input means; and audio control output means for outputting a sound corresponding to the audio signal entered by said input means if the level signal is greater than a prescribed threshold value and the period detected by said period detecting means falls within a prescribed range, wherein said period detecting means includes; means for partitioning the audio signal entered by said input means into audio signals each of a time duration T; means for further partitioning each of the partitioned audio signals into audio signals each of a time duration t; and frame period detecting means for detecting periodicity of the audio signals of time duration t. - View Dependent Claims (19, 20)
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Specification