Masking sound device
First Claim
1. A masking sound source for a sound masking system comprising a random noise generating circuit having at least two incoherent outputs, first and second low pass filters having different frequency response characteristics each connected to a respective one of said outputs for deriving a noise signal having a predetermined spectral shape within the audio frequency range, continuously adjustable contour control means connected to the filters for deriving from said noise signals a composite noise signal having a spectral shape corresponding to the setting of the continuously adjustable contour control means, and an impedance transformer having an input coupled to said contour control means to receive the composite noise signal, and having an output circuit, and power amplification means having an input circuit coupled to the output circuit of the impedance transformer and an output circuit providing terminals for connection to a loudspeaker.
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Accused Products
Abstract
A masking sound source for a sound masking system has adjustable preset means for adjusting the spectral shape of the sound produced. The source includes a random noise generator for producing white noise and having two incoherent outputs in which two low pass filters having different frequency response characteristics are connected. The filtered noise signals are applied to a potential divider forming a contour control device by which a composite noise signal having the requisite spectral shape is derived. This composite noise signal, after appropriate level adjustment, is applied to an output amplifier.
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Citations
10 Claims
- 1. A masking sound source for a sound masking system comprising a random noise generating circuit having at least two incoherent outputs, first and second low pass filters having different frequency response characteristics each connected to a respective one of said outputs for deriving a noise signal having a predetermined spectral shape within the audio frequency range, continuously adjustable contour control means connected to the filters for deriving from said noise signals a composite noise signal having a spectral shape corresponding to the setting of the continuously adjustable contour control means, and an impedance transformer having an input coupled to said contour control means to receive the composite noise signal, and having an output circuit, and power amplification means having an input circuit coupled to the output circuit of the impedance transformer and an output circuit providing terminals for connection to a loudspeaker.
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9. A masking sound source for a sound masking system, comprising:
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a noise generating circuit having at least two incoherent outputs, first and second low pass filters having different frequency response characteristics, each filter having an input and an output, the input being connected to a respective output of the noise generating circuit for deriving therefrom a noise signal having a predetermined spectral shape within the audio frequency range, a potential divider connected across the outputs of the filters and having a continuously adjustable output tap, whereby to derive a composite noise signal having a spectral shape determined by setting the potential divider, an impedance transformer having an input connected to receive said composite noise signal and having an output circuit coupled to the input circuit of a power amplifier, the power amplifier providing output circuit means for connection to a loudspeaker. - View Dependent Claims (10)
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Specification