Embedding voice – DSP chip or DSP algorithms on the Applications Processor?

Embedding voice – DSP chip or DSP algorithms on the Applications Processor? 5578 3719 XMOS

Why smart developers choose a DSP chip rather than run DSP algorithms on the Applications Processor …

In our increasingly connected, intelligent world, voice-control opens the door for a more natural, engaging conversation with technology. Reliable, accurate voice capture relies on advanced digital signal processing (DSP) algorithms and good acoustic design to ‘hear’ the wake-word and pick up the voice command – even in a noisy environment. Some of the key algorithms include:

  • Acoustic-echo cancellation: When you give a voice command to a TV, the microphones will capture both your command and the audio track coming from the TV speakers. That captured audio track – the acoustic echo – needs to be cancelled from the captured signal so it ‘hears’ the wake-word’ first time, every time and captures a clean voice command to send to the speech recognition service (eg Alexa). This is also known as ‘barge-in’.
  • Beamforming: This detects and tracks where the voice is coming from, so the command is captured accurately, even if you’re walking across the living room.
  • Interference Canceller: This ‘scans’ the soundscape of the room and ignores (cancels out) the point noise sources, ie anything that’s not the voice of interest, in the surrounding space. The improved voice signal can then be sent to the speech recognition service.
  • Noise suppression: Noise suppression algorithms target diffuse noise sources such as air conditioning and road noise. They remove the stationary and non-stationary background sounds to enable accurate, reliable voice detection.

As voice starts to move beyond smart-speakers and into the living room, developers are having to figure out how best to build a voice interface into a smart TV or set-top box. And one of the common questions we hear is whether to embed the DSP on a separate voice processor (chip) or run DSP algorithms on the Applications Processor ….

Should you run DSP algorithms on the Applications Processor?

Most consumer electronics devices are built around an Applications Processor. Put simply, the more powerful the processor, the quicker your programmes, apps, games and features will appear. As a developer, you may choose to simply execute the DSP algorithms on the Applications Processor (host processor). At first glance, this seems cost effective and easy to integrate – primarily because there’s no additional chip to purchase and integrate. However, there are some significant downsides to this approach that developers need to consider.

  • Adverse impact on capacity: because the host processor handles the core system processes, it’s one of the most expensive elements of the electrical design. The more powerful the host processor, the more tasks it can handle – but in turn, it’ll cost more, consume more power and require more space. As a developer, you’ll want the cheapest processor that’s capable of running all the core functions, with minimal power. Therefore, adding DSP algorithms onto it, imposes additional processing that burdens the chip and takes up capacity that can otherwise be used for core functions.
  • Bill of Materials (BoM): This will be pushed up beyond original estimates as additional components will be required to support the integrations (eg microphone aggregator).
  • Performance risk: The DSP algorithms will be constrained by the capacity that’s available on the host processor and performance may be compromised.
  • Integration complexity: Adding algorithms onto the host processor, puts all of the integration demands onto the software team and can rapidly increase the cost of development. It can also create challenges in delivering with in the real time constraints to produce a glitch-free audio stream, without increasing the latency of the system. Further challenges may arise in the future around in-field updates and whether there’s sufficient capacity to run the update on the host processor.

How does that compare with running DSP algorithms on a separate chip?

A standalone DSP chip solution offers some compelling advantages over licensing DSP algorithms and integrating them into the host processor.

  • Transfers work away from host processor: Running the DSP on a separate chip, keeps the host processor free for core functions – and avoids impacting the software team
  • Easy to integrate: A ringfenced solution needs to be planned into the electrical design, but using an external DSP allows you to use standard hardware interfaces (such as I2S or USB for connectivity) which simplifies the integration task significantly. A separate chip ensures there are no dependencies between the code on the DSP chip and that on the host processor, there’s simply an API to deliver processed voice samples in an uninterrupted stream.
  • Future-proof solution: You benefit from the latest developments in voice technology; plus, in-field software releases are delivered easily via firmware update.
  • Accelerated time to market: A DSP chip offers a plug and play solution which separates the voice-capture solution from the rest of the TV electronic design, enabling developers to deliver a built-in voice interface rapidly.

Choosing the right far-field voice interface for your TV or set-top box is a key decision for your company. A separate voice processor such as XMOS’ VocalFusion often provides a more flexible and cost-effective solution over the complete lifecycle of a TV or set-top box. It reduces project risk, minimises dependencies between software functions and avoids burdening the host processor.

XMOS solutions are cost-effective and offer the flexibility to remove additional costs from your system design. Find out more about our voice solutions here. Or get in touch with one of our sales team here.

We’re here to help you transform the way people find and enjoy content through your products.


The role of women in the rise of AI

The role of women in the rise of AI 310 310 XMOS

We spoke with Natalie Powell (ChannelNewsAsia) at MWC19 on the “Role of Women in the rise of Artificial Intelligence”.

Introducing Windows collaboration display by Sharp

Introducing Windows collaboration display by Sharp 629 362 XMOS

“Walk in, plug in, work together”

XMOS is collaborating with Japan-based multinational corporation Sharp to create the first Windows collaboration display (WCD) by Sharp – the next generation interactive smart touch screen designed to improve teamwork by enhancing communication through easy video conferencing and remote collaboration.

Manufactured by Foxconn, the 70” 4K interactive display combines XMOS far-field voice-capture technology, Microsoft WCD specifications and Sharp’s award-winning touch technology to transform the way people collaborate together across enterprise applications.

When video conferencing, XMOS’ far-field voice processor can capture participants’ voices accurately from up to 4 meters away, removing all the additional noise to isolate and send the digital voice stream.

Located top-centre of the display, our XVF3500 stereo-AEC voice processor delivers up-close voice capture quality and processing accuracy at far-field range, simplifying the complicated business of cleaning up sound in a noisy space during a conference call.

XMOS VocalFusion XVF3500 voice-capture technology:

  • Stereo acoustic echo cancellation: removes acoustic feedback between the display’s speakers and microphones to accurately capture voice commands.
  • Beamforming:identifies the direction the voice command comes from, even if moving.
  • Dereverberation:removes the echoes from the user’s voice as it ‘bounces’ off the hard surfaces in the room.
  • Noise suppression:removes exterior noises, e.g. air conditioning, people talking, pets etc.
  • Barge-in:enables users to interrupt when audio is being played through the device (or another source), with a voice command spoken at normal volume from across the room.

Mark Lippett, CEO of XMOS said: “This display brings together all the necessary tools into one place for a truly collaborative solution. We’re delighted to help bring this incredible new Windows Collaboration Display by Sharp to life and are proud that our voice-capture technology is playing a big part in helping people communicate effectively.”

About XMOS

XMOS is a leading supplier of voice and audio solutions to the consumer electronics market. Unique silicon architecture and highly differentiated software positions XMOS at the interface between voice processing, biometrics and artificial intelligence. For more information, please email

Mark Lippett talks about the chips that make Voice Assistants work

Mark Lippett talks about the chips that make Voice Assistants work 328 328 XMOS

Voicebot Podcast Ep 87: Mark talks to Bret Kinsella about what technologies make the far-field voice recognition feature possible in smart speakers, smart TVs, streaming media boxes and other devices.

In his own words: Esher, our intern talks about his time at XMOS

In his own words: Esher, our intern talks about his time at XMOS 4503 3002 XMOS

XMOS continues to enlighten and surprise me.

I first worked at XMOS during the summer of 2017, after finishing my second-year university exams.  On finishing university, it was a pleasure to be able to return for a second work placement. XMOS is filled with such intelligent, dedicated and friendly people, and working here, I’ve seen how effectively a team can drive to reach shared goals and grow the business to where it deserves to be. Throughout this blog, I’d like to highlight my thoughts on the work I’ve been involved with, the culture that XMOS promotes and the vision I see for XMOS as a company moving forward. It has been an absolute honour to work alongside such talented people and I’ll watch XMOS with interest in the years to come.

During this work placement, I gained a fresh perspective on the company’s vision. I’d worked with the Finance team previously, so sitting with Marketing meant new faces, new ideas and new direction. I was immediately welcomed with my own desk, my own space and a sense of belonging – which really helped me relax into the role. My time was split between the Marketing and Finance teams, so I was never short of work! It was rewarding to feel I was adding real value to the business, helping in areas where help was clearly needed. I admit that some tasks were more exciting than others, but regardless of what I was doing, I certainly honed-in on and further developed some very important skills: the use of Excel, my attention to detail, my creativity, my communication and my ability to break down the task at hand logically and systematically. The work over the last 3 months has been full of variety. I’ve thoroughly enjoyed working across different departments, gaining a great insight into XMOS and this fast-moving technology industry, but also working alongside and befriending some fascinating people.

I’d describe XMOS as open, natural and hardworking. The sense of community is really felt here and I believe it all stems from the employees. Everyone welcomed me as an equal, which made it easy for me to learn and grow as an individual. I felt a great willingness to help from everyone, regardless of their position in the company. The lack of hierarchy at XMOS is something I truly admire. Their flexibility and understanding of people’s needs is also outstanding. It’s also a company that’s serious about having fun. The lead-up to Christmas was been like no other, full of festivities and good vibes. The people I’ve been surrounded by for the last 3 months have brought me nothing but smiles and joy.

Make no mistake though, hard work and ambition is instilled in the backbone of XMOS employees. Their dedication to get the job done on time, to out-perform the competition and still look to what they can do to improve – that’s a real recipe for success and will help them scale new heights. An Indian sage once said that in a finite world, we are all looking for infinite satiation. In a never decelerating world of innovation today, where competition is considered a status quo state, it is of crucial importance to dedicate time to understand people and their behaviour. I believe that with some finer tuning and a deeper understanding of the needs and wants of XMOS employees, they’re on their way to the perfect culture.

XMOS has a bright future. Innovative ideas, great people, hard work, ambition…it’s all in the DNA of XMOS. I speak from a young generation when I say that technology is hot and exciting. The limits are endless. But let’s not forget about the fierce competition that’s contained within this field and it’s important for XMOS to compete fiercely and further expand sustainably and intelligently in this growing market. I believe innovation and adaptability is key. Providing high-qualify innovative products will put XMOS on the radar of new clients. Being adaptable will help XMOS build its brand as an intelligent company that’s aware of the current issues at hand. How can one promote innovation? For me, the core lies in being able to freely express ideas and solutions. Emphasis on the word ‘freely’: XMOS Ideas Sessions where, once a month, small, diverse groups have complete freedom to share ideas on potential XMOS improvements (be they internal or external); this could help shape the working environment, evolve the strategy or even identify a new product opportunity. Innovation stems from having many different perspectives and these Ideas Sessions may help surface even more pioneering ideas from the team.

When I think of what is to come for XMOS, I am filled with excitement and intrigue. I am grateful to have played a small part of XMOS’ journey and am excited for what the future holds. For me though, now comes a time of relaxation. A time of enjoyment, peace and exploration. I am travelling to South America, with my girlfriend, to explore and understand new cultures, new situations and new people. It is going to be a beautiful journey which I have complete trust in. During my time away, I will also be ‘chasing the wind’ – following my passion of kitesurfing. I am excited to finally dedicate myself to this sport it hasn’t been feasible to do so until now. I’m going to see many wonders during my time in Argentina, Chile, Bolivia, Peru, Ecuador, Costa Rica and Cuba, but will never forget my time here at XMOS. I’ll be returning to England in summer 2019 and am looking forward to starting the next stage of my career at KPMG as a Technology Consultant. For now, I wish nothing but success and happiness for team XMOS. We’ll meet again!

by Esher Pegrum

XMOS is hiring!

If you’re interested in finding out more about what it’s like working for a leading company in the voice capture space, with partners such as Amazon Alexa and Infineon, you can browse our jobs or send us your CV with note about why you’d like to work here to We’d love to hear from you.

Alexa and her friends are everywhere at CES

Alexa and her friends are everywhere at CES 900 506 XMOS

So is the remote control being killed-off? In the long-term, absolutely. It’s gone. “Getting rid of the remote control is one of the strongest use cases for voice technologies,” says Mark Lippett, CEO at XMOS, whose farfield voice tech is used in soundbars, Freebox and Skyworth TVs to allow them connect to Alexa. Please click the…

Mark Lippett on how XMOS has made itself heard.

Mark Lippett on how XMOS has made itself heard. 350 494 XMOS

Don’t miss Mark’s interview in the January edition of South West Business Insider, where he outlines how XMOS’ intelligent speaker technology is set to change the way we live our daily lives …

The world’s first personal assistant that beams sound only to you

The world’s first personal assistant that beams sound only to you 5360 3574 XMOS

Introducing the truly “personal” personal assistant device enabled by Audio Spotlight® directional sound technology.

Holosonics is pleased to announce it has partnered with XMOS to produce a concept design for the world’s first voice-activated personal assistant device that listens to where you are – and then speaks only to you. By combining XMOS highly directional, VocalSorcery microphone hardware with Holosonics’ patented Audio Spotlight directional speaker technology, the concept for the first and only truly “personal” personal assistant has emerged.

Unlike standard devices, where the personal assistant announces the answer to the room, this technology lets the personal assistant pinpoint the exact direction of an audio reply within a given space – it directs the answer at the person who asked the question in a narrow laser-like beam of sound, so the user gets high-quality, precisely controlled sound with none of the noise.TM

“The Holosonics team is thrilled about the partnership we forged with XMOS to bring together XMOS spatial audio capture expertise with Audio Spotlight® directional sound to create what we believe is the next level in personal assistant device technology,” said Holosonics Founder and CEO Dr. F. Joseph Pompei. “By incorporating the option of focused sound into the existing available features of a personal assistant, we find ourselves in the very exciting position of creating the next chapter in the evolution of assistive voice-activated devices.”

Mark Lippett, XMOS CEO commented: “This is a hugely exciting collaboration. Holosonics’ technology could transform the way we interact with personal assistants in future. They’ve created a more private experience, which is immediately compelling and opens up a new world of possibilities.”

Dr. Pompei and his team will demo the world’s first truly “personal” personal assistant at the XMOS suite during the Consumer Technology Association’s CES 2019 conference in Las Vegas on January 8-11, 2019.

To learn more about Holosonics’ appearance at CES 2019, please visit

About Holosonic Research Labs

Holosonic Research Labs, Inc. is a pioneer in directional acoustics, develops and manufactures the Audio Spotlight® directional sound system. Founded by MIT graduate Dr. F. Joseph Pompei, Holosonics’ Audio Spotlight® technology is used in a wide variety of applications including museums, libraries, offices, reception areas, retail displays, trade shows, and retail kiosks. The world’s top organizations and companies use the Audio Spotlight® directional sound system to beam sound to their listeners… and preserve the quiet.TM For more information, please email or phone +1 617-923-4000

About XMOS

XMOS is a leading supplier of voice and audio solutions to the consumer electronics market. Unique silicon architecture and highly differentiated software positions XMOS at the interface between voice processing, biometrics and artificial intelligence. For more information, please email

“Ok Orange!” XMOS helps bring the Orange Djingo smart speaker to life

“Ok Orange!” XMOS helps bring the Orange Djingo smart speaker to life 860 481 XMOS

The Orange and Deutsche Telekom partnership goes from strength to strength. Hot on the heels of Deutsche Telekom’s Magenta comes the Orange Djingo smart speaker, which was revealed at the Orange #ShowHello on 12 December 2018.

This smart device supports Orange Djingo and has Alexa built-in, to offer a wide range of additional services. You can use it to make hands-free voice calls, interact with Orange TV and control your ‘Connected Home’ services from Orange as well as main IoT brands like Philips Hue, Bosch.

Compact and attractive, this clever new speaker uses XMOS VocalFusion XVF3000 far-field voice capture technology with a circular microphone array. XMOS high-performance silicon and voice algorithms deliver a superior 360 degree, robust far-field voice control system that allows the user to listen to music at the same time as using voice command controls.

For more information, please visit the Orange press room.

Bristol/Paris 13 December 2018

XMOS celebrates the launch of Freebox Delta

XMOS celebrates the launch of Freebox Delta 1200 675 XMOS

Last week, innovative French telecoms operator Free, announced the launch of Freebox Delta. We’re very proud to provide the far-field voice capture capability. It was a pleasure to be part of the team, collaborating in our Bristol acoustic lab to optimise the algorithms and bring Freebox Delta to life.

Using XMOS XVF3500 stereo-AEC voice processor, FreeBox Delta has Ok Freebox and Alexa built-in – opening up a whole new experience for the smart home. Congratulations to all the teams involved – exciting times.

The Freebox Delta package is available to subscribers in France via