Earlier this month, ecobee announced its fourth-generation smart thermostat, the ecobee4, with built-in Alexa Voice Service (AVS), enabling customers to adjust the temperature, hear the news, control smart home devices, and more using just their voice. The ecobee4 is part of the company’s larger Whole Home Voice initiative, which looks to simplify how people interface with technology in the home through a series of Alexa integrations and new product launches.

Alexa and ecobee are at the forefront of voice user interface (VUI) design. We spoke with Tarun Tuli, director of embedded systems at ecobee, to learn how he and his team are approaching product development with voice control as the primary user interface.

Q1. How did ecobee get started building with Alexa?

TT: At ecobee, we believe voice is an intuitive interface, and one that will see rapid adoption by customers if done right. Our mission at ecobee is to make our customers’ lives simpler—in seeing the impact Alexa has had on customers’ lives through Amazon Echo devices, we felt that embedding Alexa in everyday devices, such as the ecobee4, made a lot of sense.

Our initial prototyping process involved many development kits all interconnected and glued together to build a proof of concept that demonstrated the functionality. We experimented with various approaches that used different numbers of microphones, different fundamental algorithms, and compared them side-by-side to determine which solutions provided the best and most robust performance in the smart thermostat category. We also focused on different aspects of the product and prototyped each one separately—device form factor and placement of microphones and speaker, far-field voice experience, speaker quality and housing. Our process involved a lot of 3-D printed prototyping to test different design ideas for ecobee4.

Q2. How has voice as a user interface changed product development at ecobee?

Our mission is to lead the smart home category into a Whole Home Voice future by bringing far-field voice technology and Alexa into every room of the home. Bringing AVS integration directly into our products enables embedded far-field voice technology into everyday devices. Having completed AVS integration into our smart thermostat offering, we are now focusing on bringing AVS capabilities to our smart light switch product, which will launch later this year.

Q3. What factors went into selecting the right mic array and development kit for the ecobee4?

Given the form factor of the ecobee4 smart thermostat, a 7-microphone solution wasn’t feasible. We wanted to evaluate and create a proof of concept solution that would be workable for the thermostat form factor, and having access to the Conexant 2-Mic Development Kit for Amazon AVS enabled us to quickly prototype and verify the efficiency of a 2-mic solution. We applied significant modifications to the algorithms that run on this kit to achieve even better far-field performance.

Q4. The ecobee4 is also the first AVS-enabled product to leverage Cloud-Based Wake Word Verification. How will this feature impact user experience?

The challenge that far-field technology needs to optimize against is sensitivity of the wake performance under noisy conditions, while ensuring the device doesn’t falsely wake. Since these two features are inversely related, improving one sometimes leads to degradation in another. With Cloud-Based Wake Word Verification (CBWWV), we were able to substantially improve wake word accuracy thereby providing customers with a better experience. The use of CBWWV is especially important for low power applications such as the ecobee4 as it permits the device to achieve the required performance without needing to have high computational requirements of a large wake word model running directly on the device.

Q5. What excites you most about the Alexa service?

AVS has quickly enabled us to offer our customers a multitude of services and skills. Amazon’s focus on increasing the capabilities of Alexa and making those capabilities available to third-party developers is really breakthrough, as it enables us to offer a voice forward experience to our customers. At ecobee, we are working on a custom Alexa thermostat skill that enhances the capability of the smart home skill, in order to provide our customers with even more control over their ecobee4. AVS is an exciting service as it opens up new possibilities for how we can improve our customers lives.

Getting Started with AVS

Alexa is always getting smarter with new capabilities and services through machine learning. As a developer, your product also gains access to new capabilities with Alexa through API updates, feature launches, and custom skills. Learn how AVS can add rich voice-powered experiences to your connected products on the AVS Developer Portal.

Have questions? We’re here to help. Visit us on the AVS Forum or Alexa GitHub to speak with one of our experts.