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Compact loudspeaker assembly
| Details |
Inventors: McAteer, Jeffrey P.; Willis, Kevin D.;
Assignee: AT&T Corp. (Murray Hill, NJ)
Primary Examiner: Dwyer; James L.
Assistant Examiner: Chiang; Jack
Attorney, Agent or Firm: Morra; Michael A.
A speakerphone comprises an upper housing member and a lower housing member that are joined together to enclose a loudspeaker, a microphone, and a printed wiring board having electronic components mounted thereon that cooperate in the operation of the speakerphone. The upper housing member includes a continuous sidewall that is molded into its underside and extends downwardly toward the printed wiring board. The sidewall surrounds a group of sound apertures that are also molded into the upper housing member. A loudspeaker is attached to the underside of the upper housing member in such a manner that it completely covers the sound apertures. A sealed enclosure within the speakerphone is formed by creating a seal between the sidewalls and the printed wiring board. A compliant gasket is illustratively used to create the seal. As a result, the frequency response of the loudspeaker is improved, and acoustic coupling between the loudspeaker and the microphone is reduced. The frequency response of the loudspeaker is further improved by inserting acoustically absorbent material, and by extending a tuned port, into the sealed enclosure. |
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DETAILED DESCRIPTION Speakerphones have grown in popularity in recent years, especially in the business environment where the convenience of hands-free communication has become more of a necessity than a luxury.
Speakerphones allow the user to move around the office during a conversation and enable colleagues to join together for a conference call.
The business user, however, exhibits little tolerance for low quality equipment and the sound quality of a speakerphone is readily apparent to its users.
The ideal speakerphone is one that reproduces a distant party's voice with great fidelity (i.
e.
, "naturalness") and enables full-duplex conversation (i.
e.
, simultaneous conversation in two directions).
Sound reproduction fidelity inherently requires that the loudspeaker provide an output sound level that is linearly proportional to its input signal level over the audible frequency range.
In other words, all frequencies must receive equal treatment, and none are amplified or attenuated more than others.
Furthermore, since the loudspeaker and a microphone generally share the same housing, the coupling between these transducers should be minimized to enhance the ability of the speakerphone circuits to provide full-duplex service.
The present invention improves loudspeaker quality in such a manner that frequency response is improved at the same time that loudspeaker-to-microphone coupling is reduced.
FIG.
1 shows a top view of a speakerphone housing with its associated handset removed.
Normally the receiver section of the handset fits into cavity 410 while the transmitter section of the handset fits into cavity 440.
The user may enter the active (i.
e.
, off-hook) state, in a speakerphone mode, by merely depressing SPEAKER key 460.
The active state is alternatively selected by switchhook 125 when the receiver section of the handset is removed from cavity 410.
During the speakerphone mode, the handset is not used.
Instead, a microphone that is built into the housing (behind sound apertures 461) is used to pick up audible sounds
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Ring Tones 
