The present invention relates to headsets. More specifically, the present invention relates to reducing wind noise in headsets.
In windy conditions, headset microphones often generate wind-induced noise, or what is often referred to as “wind noise”. Wind noise is undesirable since it disrupts speech intelligibility and makes it difficult to comply with telecommunications network noise-limit regulations.
Various different approaches to reducing wind noise, or countering its effects, are employed in communications headsets. One approach involves subjecting the wind noise to digital signal processing (DSP) filtering algorithms, in an attempt to filter out the wind noise. While DSP techniques are somewhat successful in removing wind noise, they are not entirely effective and do not directly address the source of the problem. DSP approaches also impair speech quality, due to disruptive artifacts caused by filtering.
Another, more direct, approach to reducing wind noise involves using what is known as a “wind screen.”
Wind noise can be particularly problematic in headsets that employ short-length microphone booms, as are commonly employed in modern behind-the-ear Bluetooth headsets, such as the Bluetooth headset 300 shown in
In general, the further a wind screen is separated from the microphone, the more effective the wind screen is at deflecting wind away from the headset's microphone. For this reason, prior art approaches tend to increase the diameter of the microphone boom, either along the boom's entire length, or towards the distal end of the boom, as is done in the behind-the-ear headset 300 in
It would be desirable, therefore, to have a microphone boom structure for a communications headset that is effective at reducing wind noise, yet which is also small, discreet and unobtrusive to the headset wearer.
Miniaturized acoustic boom structures for headsets are disclosed. An exemplary miniaturized acoustic boom structure includes a microphone boom housing having a wind screen and a microphone pod configured to hold a microphone. The microphone pod has an outer surface secured to an inner surface of the microphone boom housing, an interior having one or more surfaces configured to form an acoustic seal around at least a portion of the periphery of the microphone, and one or more pod port openings spaced away from one or more microphone ports of the microphone. The outer surface of the microphone pod has a wide cross-section near where the microphone pod is secured to the inner surface of the microphone boom housing and a relatively narrow cross-section at the one or more pod port openings.
In one embodiment of the invention, the microphone pod includes first and second pod port openings that provide sound wave access to opposing sides of a diaphragm of the microphone. The first and second pod port openings are spaced away from first and second microphone ports of the microphone so that an acoustic path length between the first and second pod port openings is greater than an acoustic path length between the first and second microphone ports.
Further features and advantages of the present invention, as well as the structure and operation of the above-summarized and other exemplary embodiments of the invention, are described in detail below with respect to accompanying drawings, in which like reference numbers are used to indicate identical or functionally similar elements.
Referring to
According to one embodiment, the first and second microphones 408 and 410 are directional microphones, although other types of microphones (e.g., one or more omnidirectional microphones) may alternatively be used. The directional microphones 408 and 410 are oriented within the microphone boom 402, as indicated by the large directionality arrows pointing toward the distal end of the microphone boom housing 402 in
As shown in
According to one aspect of the invention, the acoustic path length between the front and rear pod port openings 414a and 414b of each of the first and second microphone pods 404 and 406 is greater than that between the front and rear microphone ports 412a and 412b. The spacing between the front and rear pod port opening 412a and 412b of each of the first and second microphone pods 404 and 406 is designed to increase the time and amplitude differences between sound waves arriving at opposite sides of the microphone diaphragms, thereby increasing the microphones' sensitivity to sound pressure. In an exemplary embodiment, the spacing between the front and rear pod port openings 412a and 412b of each of the first and second microphone pods 404 and 406 is between about 6 and 9 mm.
According to another aspect of the invention, the outer surface of the first microphone pod 404 has a wide cross-section near where the first microphone 408 is secured to the inner wall of the microphone boom housing 402 and a relatively narrow cross-section at the front and rear pod port openings 414a and 414b. Similarly, the outer surface of the second microphone pod 406 has a wide cross-section near where the second microphone 410 is secured to the inner wall of the microphone boom housing 402 and a relatively narrow cross-section at the front and rear pod port openings 414a and 414. In the exemplary embodiment shown in
In the exemplary embodiment shown in
The diameter of the microphone boom housing 402 (or cross-sectional dimension, in the case of a non-circular cross-section boom) may be further reduced by orienting each of the microphones 408 and 410 so that their largest dimension is oriented along the length of the microphone boom 402.
According to another aspect of invention, the microphone pods 404 and 406 are made from an electrically insulating material. Accordingly, when configured in the microphone boom housing 400, the microphone pods 404 and 406 increase the electrostatic discharge (ESD) path from the metal casings of the microphones 408 and 410 to the outside of the microphone boom housing 402. The increased ESD path provides greater discharge protection for both the microphones 408 and 410 and the headset wearer. To maximize ESD protection, the microphone pods 404 and 406 can be made to be gas tight everywhere except for the front and rear pod port openings 414a and 414b.
The miniaturized acoustic boom structure 400 in
The present invention has been described with reference to specific exemplary embodiments. These exemplary embodiments are merely illustrative, and not meant to restrict the scope or applicability of the present invention in any way. Accordingly, the inventions should not be construed as being limited to any of the specific exemplary embodiments describe above, but should be construed as including any changes, substitutions and alterations that fall within the spirit and scope of the appended claims.
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