In this hands-on workshop, you learn how to build your first far-field voice-enabled product with the Amazon Alexa Voice Service (Amazon AVS). We provide you with the hardware and software you need to build this project based on the Intel Speech Enabling Developer Kit for Amazon Alexa. The workshop covers the basics of the cloud-based Amazon AVS, the Amazon AVS API and client architecture, and audio front-end design with microphone arrays and speech processing technologies from Intel. You also learn how to configure Amazon AVS devices for distribution in international markets. At the end of this workshop, you leave with a working voice-enabled prototype with Alexa on the Intel Speech Enabling Dev Kit.

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AWS re:Invent
Designing Far-Field Voice Solutions
with Intel N o v e m b e r 3 0 , 2 0 1 7

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Meet the team!
Chris Keyser
Principal Solutions Architect, Alexa
Voice Service
Sanjay Devireddy
Software Development Engineer,
Alexa Voice Service
Gagan Luthra
Sr. Product Marketing Manager, Alexa
Voice Service
Fletcher Nelson
Solutions Architect, Alexa
Voice Service
Navneet Malpani
Principal Solutions Architect, Alexa
Voice Service

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The evolution of voice interaction

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• Single microphone
• Always on
The evolution of voice interaction

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• Single microphone
• Always on
• Push to talk
• Built-in speaker
The evolution of voice interaction

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• Single microphone
• Always on
• Push to talk
• Built-in speaker
• Voice activated
• Noise cancellation
The evolution of voice interaction

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• Single microphone
• Always on
• Push to talk
• Built-in speaker
• Voice activated
• Noise cancellation
• 360-degree mic coverage
• Increased detection range
The evolution of voice interaction

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Amazon Echo: The first Alexa-enabled device
“Amazon’s Echo might be the
most important product in years”
“Amazon Echo proves the viability
of voice-based home computing.”
“Amazon Alexa just conquered CES 2017.
The world is next.”
“Alexa is clearly the star of IFA 2017”

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Hi, Alexa… Hello!

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Smart home
control
Timers and alarms
Cloud-based
intelligence
Shopping
Music
News and
information
Custom skills
Always getting smarter

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Amazon’s Alexa-enabled products

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Vision: Alexa anywhere
Home audio
Thermostats
Automobiles
Maker boards
Wearables
Small appliances
Smartphones
Large appliancesHome security
TV/video

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Alexa-enabled products

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Directives
Instructions sent from AVS to Client
Events
Information sent from Client to
AVS
Voice Hardware
Audio Front End
Device Software
AVS Device SDK
Simplifying voice interaction

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“Alexa, Play Music”
Wake Word
Engine
“Play” Directive
Intent
Recognition Result
Recognition Result
Text/SSML
Speech
Platform
Skills
Music
Service
ASR
NLU
TTS
“Recognize” Event
Streaming URL
User’s Utterance
Event
Alexa Voice Response
Directive
Intent
Alexa Voice Service
Speech
Capture via
Microphone
Play back
through
Speaker

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How do you build Alexa into your product?

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White box design End device
Continuum of reference designs
Smart speaker puck Your product

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Form factor
reference design
White box design End device
FFRD
Continuum of reference designs
Smart speaker puck Your product

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AVS-enabled
module
Form factor
reference design
White box design End device
FFRD
Systems integrator
AVS module
Continuum of reference designs
Smart speaker puck Your product

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Development kit AVS-enabled
module
Form factor
reference design
White box design End device
FFRD
Systems integrator
AVS module
Continuum of reference designs
Smart speaker puck Your product
Intel Voice Enabling
Developer Kit

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Microphone array
ADC ADC ADC ADC
Hardware architecture – What’s in an AVS client?

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Hardware architecture – What’s in an AVS client?
DSP
Amp DAC
Audio
algorithms
Microphone array
ADC ADC ADC ADC

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DSP
Amp DAC
Audio
algorithms
SoC
Wi-Fi/Ethernet
AVS client
WWE
Microphone array
ADC ADC ADC ADC
Audio
drivers
Hardware architecture – What’s in an AVS client?

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Touch activated
Interaction models – introducing terms

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Hands-free
voice activated
Interaction models – introducing terms

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Interaction models – introducing terms
Far-field
voice activated

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Choosing the right audio front end
Number of
microphones
Microphone
arrangement
Audio algorithms

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Audio algorithms
Wake word engine: Identifies “Alexa” wake word to start sending speech to cloud
• Model size:
Bigger is usually better
Requires more memory on client
• Cloud-based verification:
AVS double-checks your client’s WWE

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Audio algorithms
Responseaccuracy
Far-field Hands-free
Increasing SNR
Noise reduction: Remove background noise for clear speech capture.
SNR = Signal to noise ratio

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Audio algorithms
Problem: Audio feedback makes it difficult to pick out speech.
Voice A
Voice B
Voice A picked up by Voice B’s mic
Voice B

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Audio algorithms
Music playing
on device
Speaker output picked up by device microphone
Speaker output
Microphone
on device
Voice of user
Problem: Audio feedback makes it difficult to pick out speech.

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Audio algorithms
Acoustic Echo Cancellation (AEC): Use audio feedback to cancel echo and improve SNR.
Music playing
on device
Speaker output
Voice of user
Microphone
on device
DSP
Audio
algorithms
AEC

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First Last
Beamforming: Locate the source of speech and pick it out of background noise.
Audio algorithms

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Audio algorithms
First Last
Beamforming: Locate the source of speech and pick it out of background noise.

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Audio algorithms
Beamforming: Orientation matters!
90°
90°
15°
• Circular arrays work best at < 15° angle, such as on a table.
• Wall or ceiling mounting may negatively affect beamforming.

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Microphone arrangement
Linear array for
wall-mounted
Circular array
for tabletop

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Number of microphones
One mic for
touch activated
Two or more mics for
hands-free and far-field

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Number of microphonesResponseaccuracy
Far-field – 7 mic
Increasing SNR
Far-field – 4 mic
Hands-free – 2 mic
• Two-mic dev kits perform
comparably.
• More mics are usually better, but
result in diminishing returns.
• In high SNR environments, fewer
mics work adequately.
• As SNR decreases, even seven-mic
dev kits eventually lose accuracy.

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• Integrate high-performance voice capture
• Dev kits Include mic arrays, DSPs, SoCs
• Supported by leading chipset providers
Development kits for AVS

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INTEL
8-Mic Circular Array
XMOS
4-Mic Linear Array
AMAZON
7-Mic Circular Array
SYNAPTICS
4-Mic Square Array
CIRRUS LOGIC
2-Mic Linear Array
MICROSEMI
2-Mic Linear Array
CONEXANT
2-Mic Linear Array
AVS Development KitsHandsfreeFar-field

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Intel Speech Enabling Developer Kit
Nithyananda Jeganathan (Siva)
Product Manager , Smart Home Group
Intel Corporation
Intel helpers for the session:
Sathish Kuttan, Roberta Zouain, Ashwin Patti, Alex Z,
Yen-ning Chang, Sarah Bienvenue, Josh Cobb

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What’s included in the Intel Dev Kit?
Intel Dual DSP w/
Inference engine board
AVS Sample Client
8-Mic Array Board
Raspberry Pi™ connector
cable
Audio Pre-Processing
Algorithms, WWE, and
Software Drivers
Documentation, Collaterals,
and Software Tools

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• Devkit comes w/ premium far-field audio
certification from Amazon
• Provides a solid foundation to build new
experiences
• Accelerate new product development by
leveraging Intel’s expertise
• Intel to assist w/ audio tuning and
optimization for the product
Why use Intel developer kit?

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Intel Developer Kit— How It Works
Dual DSP w/
inference
engine
Mics
Speakers
Speech
recognition
algos
Intel Audio IP
FW
Cloud appsCloud skills
Intel Speech Enabling
Developer Kit
SW
FW
HW
Legend
Alexa voice
services
SPI
Raspberry Pi
Audio driver
AVS SDK
AVS Client
AVS Cloud
1
2
1. User utters “Alexa” keyword, and mic arrays
pickup the utterance
2. Intel’s audio far-field IP performs beamforming,
noise cancellation and detects the “Alexa”
keyword and sends event signal to AVS SDK
3
3. Keyword engine in AVS SDK receives the event
and notifies AVS client to open the channel to
driver4
4. Audio data from driver is sent to the cloud by
the AVS client
5
5. Speech recognition AI algorithms convert
audio to text and pass information to relevant
apps for processing
6
6. Cloud apps return response that is sent back
to the AVS client for playback
7
7. AVS client sends response from cloud over the
speaker

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Intel Design Optimization – Far Field on a Chip
DSP
Amp DAC
Audio
Algorithms
SoC
Wifi / Ethernet
AVS Client
WWE
Audio
Drivers
• Wake Word Engine on DSP for low power product design
• Unique to Intel developer kit
• Significant platform power savings can be realized
• Low power WoV feature has been enabled on the Dual DSP

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• 8 Mic Circular array geometry allows for precise beamforming from all directions
• Ambient noise suppression outside of the signal beam
Intel Design Optimization – Beamforming
Ambient Noise “Alexa” wake word What time is it in Vegas?

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Intel Design Optimization – Acoustic Echo Cancellation (AEC)
• Processes multichannel input signal and provides multichannel output to
algorithms
• AEC automatically adapts to room reverberation and playback signal changes
• Intel algorithms perform linear operations that does not introduce distortions
• Highly optimized for Intel Wake On Voice and Amazon Alexa performance

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Build the Sample App on your
Intel Speech Enabling Dev Kit
Open your hardware box and build your devkit!
Follow the instructions in your lab manual at:
https://avs-dvk-workshop.github.io/
W O R K S H O P A C T I V I T Y :

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Thank you!
D e s i g n i n g F a r - F i e l d V o i c e
S o l u t i o n s w i t h I n t e l
Visit the Alexa developer portal
for more information:
Documentation, tutorials ,webinars, and more
https://developer.amazon.com/alexa
AVS: Alexa Voice Service
https://developer.amazon.com/avs
ASK: Create custom skills for Alexa
https://developer.amazon.com/ask
Smart home:
https://developer.amazon.com/alexa/smart-
home