×

Masking sound device

  • US 4,914,706 A
  • Filed: 12/29/1988
  • Issued: 04/03/1990
  • Est. Priority Date: 12/29/1988
  • Status: Expired due to Term
First Claim
Patent Images

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.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×