SEATTLE (Reuters) - Amazon.com Inc AMZN.O on Thursday introduced a dozen new Echo speakers and related gadgets in a bid to stay ahead of rivals Apple Inc AAPL.O and Alphabet Inc's Google GOOGL.O in the nascent category for voice-controlled devices.

David Limp, Amazon.com Inc’s senior vice president of devices & services, introduces new products at company headquarters in Seattle, Washington, U.S., September 20, 2018. REUTERS/Jeffrey Dastin

The flurry of new products shows how the world's largest online retailer is working to make ubiquitous its voice-controlled assistant Alexa, which powers the Echo devices. It wants Alexa to be a dominant computing platform like Microsoft Corp’s MSFT.O Windows.

Amazon, at an event in Seattle, announced updated versions of its Echo Show, Echo Dot and Echo Plus, as well as new devices such as a voice-controlled microwave and wall clock. The new Echo Auto is designed to sit on a car’s dashboard and give directions or play music, while plugged into a car’s power outlet.

Shares of smart speaker company Sonos Inc SONO.O closed down 3.1 percent after Amazon announced a wireless Echo subwoofer and the $299.99 Echo Link Amp to control a home stereo system. By contrast, shares of U.S. security and alarm company ADT Inc ADT.N rose 6.6 percent after Amazon said its new Alexa Guard service could notify ADT professionals to disturbances in the home.

The new products underscore a strategic difference from Google and Apple, which so far have released fewer devices while Amazon has released many different gadgets for different purposes.

“One or more of these products is likely to resonate, but (it’s) impossible to speculate today,” Michael Pachter, an analyst at Wedbush Securities, said.

Research firm eMarketer has estimated that 40.7 million people in the United States will use Echo devices this year, up more than 31 percent from 2017. Some two-thirds of U.S. smart speaker users will have an Echo this year, versus 30 percent who will have the rival Google Home, which includes some overlapping customers.

David Limp, Amazon’s senior vice president of devices and services, who introduced the new gadgets in Seattle, said the company has made setting up the gadgets easier and has improved Alexa’s understanding of context.

“They’re going to be a lot less transactional, and a lot more conversational,” he said.

Amazon.com shares closed up 0.9 percent at $1,943.99.