Akustica's MEMS microphones target smartphones and wearables
The company has revealed four new HD voice MEMS microphones for multi-microphone applications
Akustica Inc, a Bosch Group company has added four new analogue microphones to its high definition (HD) voice product line.
These include, the AKU346, which the company says is the industry's smallest MEMS microphone to achieve 64dB SNR. Designed to meet the size-performance constraints of smartphones and the smallest wearable, the new HD voice microphones combine small footprint, high signal-to-noise ratio (SNR), tight sensitivity matching, and a super-wideband frequency response to improve intelligibility and speech-recognition accuracy in consumer-electronic devices.
New innovations in design and manufacturing enable an inherently guaranteed +/-1dB sensitivity matching between microphones. This microphone-to-microphone uniformity, along with the high SNR of the new HD voice microphones, fulfils a critical need for consumer-electronic device manufacturers who incorporate more than one microphone along with noise suppression algorithms into their devices.
These algorithms generally rely on well-matched, high-performance microphones for optimisation of noise cancellation and speech recognition accuracy.
Particularly challenging use cases for speech recognition are noisy environments and applications where the speaker is far away (over 3 feet) from the microphones. In these situations, testing has shown that even a small improvement in SNR (1-2dB) can lead to dramatic improvements in command accuracy rates (over 5 percent).
A few percentage points of accuracy can make the difference between speech recognition ubiquity and obsolescence. This has led device manufacturers to continually look for higher performance and more uniform microphones that can meet the needs of their multi-microphone application without incurring the extra costs commonly charged today for binning and sorting after final test.
"The need for the highest-performing multi-microphone solutions is growing rapidly in the smartphone market, where the average number of microphones per phone has been steadily increasing for the last few years," says Jérémie Bouchaud, director and senior principal analyst, MEMS & Sensors, IHS.
"Today, the use of two microphones has become a standard feature for smartphones. Higher-end phones can have upwards of four microphones, further increasing the need for high SNR and tighter sensitivity matching like that provided by Akustica's new microphones."
Bouchaud also points out that MEMS microphones achieving ≥64dB SNR comprise the fastest-growing portion of the overall MEMS microphone market and are expected to generate 50 percent of the revenue of this important market segment by 2017.
With a footprint of 6mm2 and a height of 0.93mm, Akustika says the AKU346 utilises 33 percent less design space than a typical industry standard bottom-port microphone but still achieves a 64dB SNR. This makes it well suited for use in small wearable accessories such as wired and wireless headsets, smartwatches and glasses.
The AKU143, AKU345, and AKU344 are top- and bottom-port microphones with a higher SNR of 65dB, and are footprint and pin-for-pin compatible with previous generations of Akustica HD voice microphones. The industry standard form factors of all three microphones provide a straightforward path for upgrading performance of current designs.
All four of the new microphones can also support ultrasonic applications such as gesture recognition, gaming, pens and location detection.
Akustica's new generation of HD voice microphones round out the Bosch portfolio of MEMS sensors, supporting the human-machine interface (HMI) within consumer-electronic devices.
Additionally, Akustica's customers benefit from the additional economies of scale gained by manufacturing in Bosch's advanced 8" (200mm) wafer fabrication facility in Reutlingen, Germany. "In-house MEMS design and manufacturing speeds new product development and allows us to be a reliable and valuable partner for our customers," says Horst Muenzel, CEO and general manager, Akustica.
"We are committed to delivering new and compelling features to our customers while also adhering to stringent Bosch principles of quality and environmental responsibility. As a result, our customers know they can depend on us to deliver high volumes of MEMS microphones on time and in-spec with the high levels of performance, quality, and reliability that they have come to expect from Bosch."
