STMicroelectronics demonstrates multiple MEMS microphones set ups with boards containing multiple mics, here four. (Source: STMicroelectronics) Click here for larger image
Many of STMicroelectronics customers are experimenting with multiple-microphone set-ups which the company demonstrates with its own evaluation boards. Multiple microphone arrays can cancel noise by subtracting out the part of the signal that is common to all microphones, as well as beam steer -- that is "aim" the microphone at the speaker by determining which unit is receiving the most consistently louder sounds.
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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