Mechanical Design Solutions for Wind Resistant Microphone Ports

Sammanfattning: This project’s objective was to gather knowledge of ways to mechanically increase speech intelligibility and decrease wind noise through the design of microphone ports. The project focused on ports that would be applied in outdoor intercom products. The project used experimental testing through the development method Robust Design to investigate different parameters that could be changed in a microphone port. This was done to further understand how changes of the parameters could give the microphone the best chances of producing high speech clarity when challenged by wind. A total of 18 port designs were tested through the human-centered method of speech-in-noise testing to evaluate the generated speech intelligibility of the ports. The designs were tested in several different noise setups to evaluate their ability to yield good speech clarity regardless of the mounting of the product or changes in wind direction. The iterative development process, conducted in two cycles, was able to conclude that conically shaped ports with a length of 20 mm produced the highest voice clarity in a varying and challenging wind environment. The ports could be positioned both facing forward and downward under the condition that a forward-facing port would need a mesh or foam windscreen added in the port for desirable performance. The project was also able to conclude that the phenomenon of destructive interference could have a significant impact on the performance of a microphone and should always be considered in the placement of a port.