Gesture control: five Knowles MEMS mics triangulate finger position
Knowles claims its SPH0641LU4H-1 is the first digital MEMS microphones specifically designed to respond to 80kHz ultrasonic signals, allowing them to triangulate the position of your fingers above the touchscreen for easier 3-D gesture control of the smartphones or tablets. Click here for larger image
By installing up to five Knowles ultrasonic microphones around the edge of a smartphone or tablet screen, software can accurately triangulate the positions of the fingers, allowing mid-air gestures to control the screen, such as turning pages by swiping your hand laterally or bringing up auxiliary control panels by swiping up-and-down in mid-air. Instead of only controlling existing functions that are already under touchscreen control, Knowles predicts that smartphone and tablet makers will come up with a whole new array of 3-D mid-air gestures, such as zooming in and out by moving your open palm closer or further away from the screen. The ultrasonic field also extends beyond the boundaries of the edge of the screen, allowing all types of new off-screen gestures to control the screen without obscuring it with your hands. Besides developing touchless gesture recognition, Knowles is also exploring ultrasonics for easier phone-to-phone data transmission and pen input for handsets and tablets.
All your arguements for digital outputs are valid, and in fact the first startup's first microphone (Akustica) had digital outputs. Unfortunately, its kind of like the VHS versus Beta video take war--if you can remember that far back--everybody was already set up for analog mics (electrets) so much so that even Akustica has had to acquiesce a prodeuce analog models. But I am with you, and think hat eventually all MEMS mics will be digital.
It would be interesting to know how far digital microphones (DMICs) -- MEMS mics that include the A/D converter -- have penetrated within the overall MEMS mic market. From an interface perspective, integrating the A/D into the same package as the MEMS makes so much more sense -- especially for applications requiring many microphones (beam-forming arrays, etc.). From the perspective of the audio processor at the receiving end, the two-wire PDM data & clock interface from a DMIC is so much easier to handle than a low-level analog signal, that it's probably well worth the extra cost of the MEMS mics with built-in A/D converters.
Oh that's an answer with fact figures; my estimation was based on the observation of my own. But yes it is very true that MEMS Mics will be having more chances of acceptance in other left out application with possible use of it for betterment.
Your are right too. Even though there are MEMS mics with HD quality, here is the breakdown on where they are used today (according to IHS)-- mobile phones (70 percent), tablets (13 percent), MEMS mics in headphones that manufacturers supply with their smarphones (9 percent), laptops (6 percent) and wearables (2 percent).
You are right many applications of MEMS Mic array are under development in many different areas, in the filed of mechanical engineering, environmental science, medical electronics etc. Soon many products will be in the market using MEMS Mic arrays. Although these Mics are still not being tried as conventional microphones that are used in live performances.
Beside smartphones, tablets all use MEMS microphones, also many PCs are switching over because they can locate mutiple MEMS in the bezel for noise cancelling and beam stearing. Apple's smart watch due this fall will use MEMS microphones also video camera, still cameras and digital recorders are all moving to MEMS mics. For the next generation, wearables will use MEMS mics and portable medical devices and the list goes on.
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