06888945 is referenced by 15 patents and cites 35 patents.

A sound masking system for a multi-occupant work area includes a masking signal generator generating incoherent masking sound signals loudspeaker modules interconnected in a daisy-chain fashion, with each loudspeaker module receiving the masking sound signals on input connections and transmitting them to a successive loudspeaker module on output connections. The connections on which the masking sound signals appear in each loudspeaker are shifted by the inter-loudspeaker connections, such that successive loudspeakers automatically emit different masking sound signals for improved diffuseness in the overall masking sound in the work area. Each loudspeaker module has one jack having the input connections and another jack having the output connections, and each jack receives a detachable cable such as telephone cable to connect adjacent loudspeaker modules. The masking sound signals are shifted by a cross connection network between the two jacks in each loudspeaker module.

Title
Personal sound masking system
Application Number
9/780978
Publication Number
6888945 (B2)
Application Date
February 9, 2001
Publication Date
May 3, 2005
Inventor
Thomas R Horrall
Harvard
MA, US
Agent
Weingarten Schurgin Gagnebin & Lebovici
Assignee
Acentech
MA, US
IPC
H04R 003/02
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