The device, which would tether wirelessly to a smartphone, is designed to look like a regular pair of spectacles so that it could be worn comfortably and unobtrusively, the people said. A bone-conduction audio system would allow the wearer to hear Alexa without having to insert headphones into their ears.
The glasses are not Amazon's only upcoming Alexa product launch. The Seattle-based group is also said to be expanding its "smart home" hardware line-up with a new home security camera system. The internet-connected camera would tie into its Echo products, for instance allowing people to view the video feed on Echo Show's screen, and letting Amazon customers see when their orders from the site have been delivered to their doorstep.
One or both of these products could be launched before the end of the year, alongside updates to existing Echo devices, said the people with knowledge of Amazon's plans.
Amazon declined to comment.
While Amazon has had its fair share of failures - including the Fire phone, whose high-profile flop ended in a $170m writedown - the success of the Alexa devices has emboldened Amazon's push into the home.
Proximity to customers, and the ability to listen to them and respond to their needs, makes the Echo devices a key portal for Amazon. The company has sold "tens of millions" of Alexa-enabled devices worldwide.
Its plans for Alexa show Amazon is willing to take risks in new technologies and double down on areas of proven success.
Internet-connected security cameras are already a mainstay of the smart home. Products from big companies including Alphabet-owned Nest and Netgear, and start-ups such as Ring, August and Lighthouse, have shown a home camera can be a popular accessory even as other smart-home devices struggle to connect with mainstream consumers.
Amazon's secretive Lab 126 product development team has been given the task of studying the smart-home market to see what other devices might make sense for the company to build.
Launching a pair of smart glasses, however, is an unexpected and riskier move, given the category is almost entirely unproven among consumers.
Google Glass was introduced with huge fanfare in 2012 but was scrapped before a full consumer launch because of concerns about privacy, price and performance. Other smart glasses experiments remain in their infancy, including Snap's Spectacles that can shoot short bursts of video, and Vue, a start-up that raised $2.2m on Kickstarter last year for what it pitched as "the world's first pair of smart glasses that are stylish and discreet".
Nest, the "smart home" division of Alphabet, unveiled new devices of its own on Wednesday. It showed off an outdoor security camera, "smart" doorbell and full home alarm system. Drawing on the AI capabilities of sister company Google, it will have facial recognition technology built into its doorbell and Google's smart home assistant embedded in its in-home security cameras.
A wearable, always-on Alexa communicator could allow Amazon to overcome one hangover from its failure in the smartphone market. While iPhone users can call Siri, and Android users can summon Google's Assistant, simply by speaking their name, the Alexa app can only be accessed by unlocking the phone and opening an app.
In 2014, Amazon hired Babak Parviz, founder of Google Glass, who has been closely involved in its Alexa spectacles project. Several other Glass researchers, engineers and designers also have moved to Amazon's labs, analysis of LinkedIn profiles shows.
Amazon's glasses are likely to do away with the camera and screen that made Glass so controversial among privacy campaigners. Dropping those features would also improve the poor battery life that plagued Google's headset.
The glasses also could provide a platform for Amazon to move into the emerging market for "augmented reality" goggles. Microsoft, Magic Leap, Apple and Facebook are working on various headsets that would display digital images in front of the viewer's eyes.