Partition system for open plan office spaces

• US 4,476,572 A
• Filed: 09/18/1981
• Issued: 10/09/1984
• Est. Priority Date: 09/18/1981
• Status: Expired due to Fees

• Current Assignee: Bolt Beranek and Newman, Inc.
• Original Assignee: Bolt Beranek & Newman, Inc. (Verizon Communications Inc.)
• Inventors: Horrall, Thomas R., Hirtle, Parker W.
• Primary Examiner(s): Cangialosi, Sal
• Application Number:
  US06/303,496
• Time in Patent Office: 1,117 Days
• Field of Search: 179/1.5 M, 179/1 AA, 381/71, 381/73
• US Class Current: 381/73.1
• CPC Class Codes: G10K 11/1754 Speech masking
• CPC Class Codes: H04K 2203/12 for acoustic communication
• CPC Class Codes: H04K 2203/34 involving multiple cooperating jammers
• CPC Class Codes: H04K 3/825 by jamming

Abstract

The partition system disclosed herein incorporates apparatus for generating a speech masking acoustic field. Respective speakers are mounted near the bottom of each of a plurality of partition panel segments defining each work space and are aimed horizontally. These speakers are driven by respective signals which are subjectively incoherent as to frequencies of interest in the masking spectrum, thereby to provide a sound field without perceptible discontinuities.

Claims

1. A partition system for open plan office spaces, said system comprising:

a plurality of vertical partition panel segments, said panel segments each including at least one speaker mounting aperture adjacent floor level;

in each of said apertures, a loudspeaker assembly providing essentially similar front and back acoustic radiation characteristics, said loudspeaker assembly being aimed horizontally along the floor, whereby the ears of a person walking toward the respective panel segment move progressively off axis as the speaker assembly is approached;

signal source means for generating a plurality of separate broadband noise signals, each signal having a spectral content compensated for the frequency response characteristic of the loudspeaker assemblies to produce, in the office space adjacent the respective panel, an acoustic spectrum for speech privacy masking, the separate signals within said plurality being incoherently related as to significant frequencies within the masking spectrum; and

means for applying each of said signals to energize a respective speaker assembly radiating into each space enclosed by said panels, so that a plurality of different signals are radiated into each such space, whereby an essentially uniformly distributed masking field is created in each such space which minimizes perceptible acoustic patterns in said field that cause the positions of said loudspeaker assemblies to be apparent.

2. A partition system as set forth in claim 1 wherein said source means includes a pseudo-random number generator.

3. A partition system as set forth in claim 2 wherein said pseudo-random number generator comprises a clocked shift register having a multiplicity of stages with feedback derived from at least a pair of stages being applied to the input of the shift register.

4. A partition system as set forth in claim 3 wherein each of said loudspeaker assemblies is aimed horizontally parallel to the floor so that the ears of a person walking move progressively off axis relative to the speaker assembly as the person approaches the respective panel segment.

5. A partition system for open plan office spaces, said system comprising:

a plurality of vertical partition panel segments, each segment comprising a flat central core constructed of a hard dense material and faced on each side with a porous sound absorbing material, a plurality of said panel segments including at least one speaker mounting aperture adjacent floor level;

mounted in each of said apertures, a loudspeaker assembly providing essentially similar front and back acoustic radiation charactertistics, said loudspeaker assembly being aimed horizontally along the floor;

signal source means for generating at least three separate broadband noise signals, each signal having a spectral content compensated for the frequency response characteristic of the loudspeaker assemblies to produce, in the office space adjacent the respective panel, an acoustic spectrum for speech privacy masking, said separate signals being incoherently related as to significant frequencies within the masking spectrum; and

means for applying each of said signals to energize a respective speaker assembly radiating into each space enclosed by said panels, so that a plurality of different signals are radiated into each such space, whereby an essentially uniformly distributed masking field is created in each such space which minimizes perceptible acoustic patterns in said field that cause the positions of said loudspeaker assemblies to be apparent.

6. A partition system as set forth in claim 5 wherein said source means comprises a shift register having a multiplicity of stages and clocked and operated as a pseudo-random number generator and wherein each of said broadband noise signals is obtained by logically combining at least a pair of signals obtained from different stages of said shift register.

7. A partition system as set forth in claim 6 wherein each pair of signals is combined in an exclusive-OR logic gate.

8. A partition system as set forth in claim 6 further comprising a respective filter for each combined pair of signals for adjusting the spectrum in accordance with the response characteristics of the speaker assemblies.

9. A partition system for open plan office spaces, said system comprising:

a plurality of vertical partition panel segments, said panel segments each including at least one speaker mounting aperture centered in the order of seven inches above floor level;

mounted in each of said apertures, a loudspeaker assembly providing essentially similar front and back acoustic radiation characteristics, said loudspeaker assembly being aimed horizontally along the floor;

a pseudo-random number source means for generating at least three separate broadband noise source signals, the different signals being incoherently related as to significant frequencies within the masking spectrum;

for each of said source signals, a respective filter for adjusting the spectral content of the signal in accordance with the frequency response characteristics of the loudspeaker assemblies to produce, in the office space adjacent the respective panel, an acoustic spectrum for speech privacy masking; and

means for applying each of the filtered signals to energize a respective speaker assembly radiating into each space enclosed by said panels, so that a plurality of different signals are radiated into each such space, whereby an essentially uniformly distributed masking field is created in each space which minimizes perceptible acoustic patterns in said field that cause the positions of said loudspeaker assemblies to be apparent.

10. A partition system for open plan office spaces, said system comprising:

a plurality of vertical partition panel segments, each segment comprising a flat central core constructed of a hard dense material and faced on each side with a porous sound absorbing material, a plurality of said panel segments including at least one speaker mounting aperture adjacent floor level;

mounted in each of said apertures, a loudspeaker assembly providing essentially similar front and back acoustic radiation characteristics, said loudspeaker assembly being aimed horizontally along the floor;

a pseudo-random number generator including a clocked shift register having a multiplicity of stages and feedback derived from at least a pair of said stages;

a plurality of gate means, each operative to combine a respective pair of signals obtained from different stages of said shift register thereby to generate at least three separate broadband noise signals, said broadband noise signals being incoherently related as to significant frequencies within the masking spectrum;

for each of said broadband noise signals, a respective filter for adjusting the spectrum in accordance with the frequency response characteristic of the loudspeaker assemblies to produce, in the office space adjacent the respective panel, an acoustic spectrum for speech privacy masking; and

means for applying each of said signals to energize a respective speaker assembly radiating into each space enclosed by said panels, so that a plurality of different signals are radiated into each such space, whereby an essentially uniformly distributed masking field is created in each such space which minimizes perceptible acoustic patterns in said field that cause the positions of said loudspeaker assemblies to be apparent.