Controlled acoustic waveguide for soundproofing
First Claim
1. Controlled acoustic waveguide for use with an elongate hollow chamber, connected to at least one sound-transmitting duct via an opening on its first end surface thereof, comprising a microphone for detecting membrane vibrations so as to allow tunability of longitudinal resonances of the hollow chamber to a sound spectrum to be attenuated, the microphone being located directly in front of a membrane of at least one loudspeaker on a second end surface of the hollow chamber, and an amplifier for inverting a microphone signal, with feedback of the inverted microphone signal to said loudspeaker being in an amplified form in dependence on a sensor signal characteristic of sound in the sound-transmitting duct.
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Accused Products
Abstract
The invention relates to a controlled acoustic wave guide configured as an elongated hollow chamber (1) which via an opening (2) in its first face end (3) is connected to a sound-conducting channel (4). The longitudinal resonances of the hollow chamber (1) can be adjusted to a sound spectrum to be dampened. To this end diaphragm vibrations are detected by means of a microphone (10) which is positioned directly in front of the diaphragm (8) of at least one loud-speaker (9) at the second face-end (6) of the hollow chamber (1). The microphone signal is then inverted using an amplifier (11) and fed back to the loud-speaker (9) after amplification in accordance with a sensor (12) signal characterizing the sound spectrum in the channel (4).
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Citations
14 Claims
- 1. Controlled acoustic waveguide for use with an elongate hollow chamber, connected to at least one sound-transmitting duct via an opening on its first end surface thereof, comprising a microphone for detecting membrane vibrations so as to allow tunability of longitudinal resonances of the hollow chamber to a sound spectrum to be attenuated, the microphone being located directly in front of a membrane of at least one loudspeaker on a second end surface of the hollow chamber, and an amplifier for inverting a microphone signal, with feedback of the inverted microphone signal to said loudspeaker being in an amplified form in dependence on a sensor signal characteristic of sound in the sound-transmitting duct.
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14. Method for absorbing sound using a controlled acoustic waveguide, comprising:
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connecting an elongate hollow chamber to a sound-transmitting duct via an opening on a first end surface of the hollow chamber, locating a microphone directly in front of a loudspeaker on a speaker on a second end surface of the hollow chamber, detecting membrane vibrations of the loudspeaker via the microphone, inverting a microphone signal representative of the detected membrane vibrator, and amplifying and feeding both the inverted microphone signal to the loudspeaker in dependence on a signal characteristic of sound in the sound-transmitting duct.
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Specification