New "smart" MEMS microphones enable recording with a quality once reserved only for musicians and rich wannabes with their own private recording studios.
Remember what a big hit Guitar Hero was when it first came out? All of us air-guitar amateurs were able to justify and perfect our skills at playing in a rock band—all in the comfort of our family rooms. If you are a MEMS-nerd like I am, you may recall that MEMS played a significant role in the success of the Guitar Hero. (Without the tilt motion-sensing provided by the MEMS accelerometer inside, we might as well be playing "Kumbaya" instead of "Walk this Way.")
After hearing the beautiful sound achieved with the high-performance MEMS microphone that Rob O'Reilly of Analog Devices demonstrated at Sensors Expo 2012, I have the same kind of anticipation for what kind of rock star(s) this MEMS device might unleash. Because what makes this MEMS mic so different is that the quality of the sound is so clear and perfect that it can make anyone sound like a rock star, sans the million-dollar recording studio. What's more, my sources at Analog Devices tell me that this new "smart" MEMS is also lower cost.
[ARM TechCon 2012, the largest ARM design ecosystem under one roof, is Oct. 30 - Nov. 1 in Santa Clara. Click here to learn more]
What makes it smart? According to the folks at Analog Devices, their MEMS microphone technology provides a higher signal-to-noise ratio for better near and far-field performance, flatter frequency response and noise rejection, ultimately producing better quality sound. Throw beam forming, directionality and proximity response into the mix and you have a microphone for a wide range of applications.
With all deference to the Walt Disney Company, I asked Rob O'Reilly how ADI makes the magic. "With our MEMS microphone, we integrate more of the signal chain than any other MEMS mic by integrating a MEMS transducer with a proprietary audio ASIC that leverages our decades of audio signal-processing experience," he replied.
In this video clip, you can learn more about the MEMS mic from my interview with Jerad Lewis, microphone applications engineer at Analog Devices.
There are several MEMS manufacturers in the MEMS microphone space including Akustica (part of the Bosch Group), Knowles, STMicroelectronics (jointly developed with their partner OMRON), and a few other smaller players. I don't want to start a contest of whose MEMS mic is "better." I happened to hear Rob's demo, and was astounded by the sound quality. I am all ears if anyone else wants to demo the amazing qualities of their MEMS microphone. Or you can hire me to record a little something for the Grammys. That would be good, too!
I agree. I got the chance to test some MEMS microphones from Wolfston last year. I compared them to the standard Electret microphones and there was no comparison. The MEMS are far superior, lighter and more sensitive.
There is no doubt in my mind that Electrets are dead. If your product isn't using MEMS, then your customers will want better.
Just my opinion.
Sorry, I have to jump on this comment as it propagates some misconceptions. MEMS are not "far" superior. Their main advantage is they can be surface mounted, but now there are electrets that can withstand the temperature required for surface mounting and there are electrets just as small. MEMS have good SNR, but only if you test them at say 94 dB SPL. They have higher noise floors than the better electrets (which can have very low noise floor), making them less usable for pickup from distant sound sources. Also, their resonance can be very peaky, and when coupled to a plastic hole their resonance frequency can be very low frequency -- not usable for anything but narrowband voice. Further, afaik there are still no unidirectional MEMS microphones, though somebody may enlighten me on recent developments. For cell phones, MEMS are mostly a win, for many other applications an electret should be considered.
I'm looking forward to improved feedback systems in noise cancelling headphones. Who knows, maybe they will be able to design a product that cancels noise over the full frequency range, not just "airplane noise".
MEMS microphones are almost replacing the condenser microphones. Mems can be integrated,compact and with stands more vibrations without performance degradation.Also they are manufactured within plus minus 3 db sensitivity which means less difficulty for the manufacturers to test their products for its uniformity. The analog devices makes it with 62-dB (typical) signal-to-noise ratio (SNR), 20-kg and 160-dB mechanical and sound-pressure shocks, respectively, and power supply rejection ratios (PSRRs) of 80 dB (digital version) and 50 dB (analog version).
"...what makes this MEMS mic so different is that the quality of the sound is so clear and perfect that it can make anyone sound like a rock star..."
I'm sorry, but as someone whose worked in the recording industry for years and sat through good sessions and bad ones I couldn't help burst out laughing when I read that.
Seriously, I do think MEMS technology is a potential breakthrough compared to electrets particularly in the low-cost sector. If they're that good I'm wondering when we'll see them used in the high-end acoustic measurement sector.
Did I miss a link to that demo sound file?
As an engineer and amateur musician I also feel like commenting your quoted sentence. Isn't it a role of a microphone to convert my voice so that when played back it sound as close as possible to what I really sound like and not to make me sound like someone else (let it be a rock star, Pavarotti or whoever!)? So if those ADI MEMS mics change the sound of my voice they aren't good at all! :)
It seems to be a poor choice of words. I see nothing in the signal chain of this mic that would do anything more than a best effort to make your voice sound as close as possible to what it really sounds like -- no built-in autotune!
Yes, MEMs mics are making great strides and the ease with which they can be interfaced lends to advances in signal processing of the sound on-the-fly (creating a psudo-unidirectional mic using phased elements). So far however, the only truely innovative MEMs mic that I have seen is the MicroFlown molecular flow sensor. It has the potiential to extend its applications into something as diverse as chemical sensing. It is just too expensive to even play with, much less incorporate into an instrument. Just mentioning it because your article did not make note of it.
Please give me a break! If you believe that MEM mics are getting even remotely close to those used in recording studios, you're the victim of consumer hype! A dynamic range of 60 dB is truly pitiful compared to a Neumann or even a Shure SM57 ... either of which can easily achieve 120 dB+ dynamic ranges. In the context of trendy, pocket-sized consumer stuff or large arrays for special applications, yes they're making progress (maybe even significant progress) but comparing them with a real recording studio setup is ludicrous. - Bill Whitlock, chief engineer, Jensen Transformers (and manager of electronic engineering at Capitol Records 1981-1988)
MEMS mics -- especially when combined with nanocoating -- have made a tremendous impact for hearing aids & cochlear implants by greatly increasing reliability to shock, vibration, and moisture.
This is vitally important in the pediatric market, where infants & toddlers cannot convey to parents & teachers that there is a problem.
Editor, The Hearing Blog
HI everyone! I am so pleased to see such an animated discussion about MEMS microphones - and yes @mediatechnology - the link to the demo file is missing in the story (sorry about that) - I'll look into getting it uploaded somewhere by my friends at Analog Devices. I guess I have this Pollyanna-ish view that Rockstars have good voices (I am sure all do not). :)
@Brakeshoe - Recently at a conference I held at UC Berkeley we had another MEMS mic company, Knowles Electronics, talk about the use of MEMS mics in hearing aids and their cross-over into consumer applications. You can check out my org's website for more info: www.memsindustrygroup.org. Thanks everyone and keep the comments coming - I love it and look forward to more on my next blog.
What other topics in MEMS would you like me to write about?