Inside view on mic technology developments with Biamp DSP engineer

Anna Mitchell catches up with Iain McCowan, senior DSP engineer at Biamp Systems, about microphone technology developments and what we can expect form conferencing systems in the future.

AM: Are there any important emerging technologies that will improve the capture and processing of speech in conference environments?

IM: The emerging technology I am most involved with is microphone array technology including beam forming and voice tracking. It's been something that is well established in research and the technology is well understood but it's only really starting to emerge to its full potential in products now. 

The have been a few companies releasing more sophisticated microphone array products in the last 12 months and I that is going to continue. Before now there's certainly been the odd microphone array product out there and the technology has been integrated into some equipment like laptops and smart phones. 

But, in terms of true conferencing arrays that are forming a directional beam from each speaker and tracking them, and tracking multiple people in real time; this is really new technology that is going to shape things over the next couple of years. 

AM: Where have the biggest recent advances been made?

IM: It’s the convergence of many factors. Not just one. 

MicroElectrical-Mechanical System (MEMS) microphones have been in smart phones and tablets and laptops for the last five to ten years and really the quality of those microphones is coming to the level of professional voice acquisition, suitable for conferencing applications. 

They have several benefits when used in an array. They are very highly calibrated elements. They are very well matched to each other so that makes them useful for arrays and also they are very small and easy to manufacture. 

Other advances have been made in the rise of processing power and the constant rise of computational power on DSPs.  

Better manufacturing techniques are helping as well as the convergence and the integration of technologies like AEC and how that integrates that with microphone arrays and beam forming. 

So I think it's just been a convergence of all these technological factors that are coming together to make advanced microphone arrays possible. 

If you look at the early ones that came out to the market ten years ago, they might have four little microphones in them and just to a single beam form directly in front of them, maybe useful for desktop PCs. Now you've got eight microphones or sixteen or even more in some of the new products. They're forming not just one directional beam but three in parallel.

AM: Why have MEMS microphones advanced so significantly?  

IM: I think more money went into MEMs microphones because it was driven by consumer technology. If you looked at MEMs microphones ten years ago they were low quality, low bandwidth microphones suitable only for mobile phones. Mobile phone quality was bad ten years ago. 

However, now so much has been invested in the mobile device space. Because of that investment and people's expectations as to the level of audio quality that you get from a mobile device the quality has increased and increased. 

I guess it's a bit of an arms race between all the manufacturers of smart phones and mobile devices to make their audio better and better. So the MEMs technology has benefited from that to the point where they are now providing good enough quality to use them in the professional conferencing environment.

AM: Where do you see future advances? 

IM: One field that I think is having big advancements at the moment is automatic speech recognition. In the last couple of years this technology has really seen a leap in performance with new algorithms coming out of some of the big research labs at companies like google. 

Looking at that field it might be interesting to see five or ten years time if speech recognition technology has more of a place in a conferencing environment. I don't think we're there yet but I can see that technology advancing to the point where it might become feasible that it would turn up in conferencing products down the path. 

AM: What advancements have been made in easing the process of set up, correct mic placement and configuration?

IM: I think we're very conscious of set up requirements. Good audio quality is the main thing you want from a conferencing system and it's not easy to get right. More and more we're trying to engineer products that do it automatically for you. 

In our Devio product we've got an auto room tuning feature for example, which helps with setting optimal sound levels or getting the gain right. The advantage of microphone array technology and beam forming and tracking of voices is you no longer have to think about how you place the microphone on the table. The microphone itself is intelligent you just place it in the middle of the table and it will automatically detect where people are, when they're speaking and steer the microphone toward them. We intelligently mix different voices if people are speaking round the table. 
I think these features are increasingly becoming the norm as developers automate functions to the point that a product can be taken out of the box, placed on a table or mounted on a ceiling and just work. 

Increasingly IT departments are managing conference rooms instead of having dedicated AV people to set them up. It’s important to give the IT staff admin the tools that they're used to so they can see all the devices on the network, they can run automatic set up, they can see any problems and they can monitor how things are going. All of that diagnostic and  monitoring software is part of the Devio management system. 

Its administration utility is designed to simplify monitoring across an entire organisation. The product is designed for one person to install a single Devio unit if they want but it can also scale up to an organisational level and there are tools to support that. 

AM: Must a compromise be made between good quality audio and maintaining sleek room aesthetics?

IM: It’s getting to a point where it's more discreet and you can get good quality audio from something that's not obtrusive to use. As engineers we're continually chasing that goal of getting the audio technology to the point where you remove any constraints on the user or the design of the environment. There's a caveat to that obviously. 

There's no getting around the fact that if you can get a microphone close to someone’s mouth, and directly in front of them, that will always be the optimal situation.   
I think the goal - particularly with microphone array technology - is smaller, sleeker table top products. So we're getting there but I think there is still room to improve further.

Biamp features in a wider article on microphone technology that you can read here.
More Q&As in the series:
Duncan Savage, systems group manager, Shure UK
Sandra Kellermann, conference business development manager EMEA at Audio-Technica
Jens Werner, portfolio manager for Business Communication, Sennheiser
Malcolm Crummey, sales manager UK & Ireland, TOA 
Romano Cunsolo, director of marketing and business development, Xavtel

Article Categories

Most Viewed