Amazon is offering other manufacturers free use of its smart speakers' microphone technologies as part of its efforts to spread the use of its Alexa virtual assistant.
The firm will, however, pick and choose who can take advantage of the proposal.
The initiative follows the launch of the Google Home speaker and its associated Assistant.
One expert said the two tech firms were now involved in a "land grab" to become the sector's number one player.
Doing so will help attract developers, and in turn ensure that one product has a wider range of capabilities than the other.
A spokesman for Amazon said the announcement was not meant to signal that it had become less committed to developing its own Echo speaker range, which uses Alexa.
"Our vision is for Alexa to be everywhere, and that means making it available to other companies and services to integrate into a wide range of devices," he explained.
"We expect Alexa to be in many devices over time, including products that compete with Echo, which is why we're investing in making a wide range of hands-free and far-field reference solutions available to OEMs [original equipment manufacturers]."
Amazon's invite-only offer includes:
- the right to replicate the seven-microphone array it uses in its own products to hear voice commands from across a room
- the use of proprietary algorithms used for wake-word recognition, focusing on an owner's voice, and handling problems such as echoes and other noises
Those taking advantage of the scheme will be given a reference kit as a starting point for their own designs, and the freedom to source components from a range of parts manufacturers.
Amazon does not reveal sales figures for its Echo devices, but analysts have estimated that more than eight million have been sold in the US alone since their launch in 2014.
The speakers are also available in the UK, Germany and Austria.
Amazon has also formed partnerships with LG, Ford and Huawei, among others, to build Alexa into products including fridges, cars and smartphones.
Google released its rival voice-activated Home speaker last November, which is powered by Google Assistant - a variation of the digital helper it developed for Android handsets.
Many smartphone-makers have since adopted it, and Nvidia has added the tech to its latest TV set-top box.
"Amazon needs to be very careful that it isn't eclipsed by Google," commented Ben Wood from the tech consultancy CCS Insight.
"Google can just roll the Assistant out to hundreds of millions of Android smartphones, so people get it by default, whereas Amazon has to work harder to get Alexa into people's hands or appliances.
"This offer shows Amazon has fully understood the hardware is just a means to an ends and that the real prize is getting people to use its platform, because scale gives such an advantage in this field," he added.