Natural language processing (NLP) is an important requirement for many AI systems. It's the same technology that powers Apple's Siri, Amazon's Alexa, and Facebook's M. But language can be problematic when you attempt to use machines to understand it. For example, if you say you want to meet at 2, it's important to know that you mean 2 p.m. and not 2 a.m. An NLP engine needs to learn the difference, and that requires large volumes of categorized data. Human expertise is required to create those training datasets.

Amazon has added a new voice recognition feature to its Alexa smart assistant. It allows the smart speaker and apps to recognise users from their voice, and personalise information to them. It comes just days after Google, which already has a similar feature in its Assistant, launched a raft of devices in its bid to topple Amazon in the personal AI war. Amazon's new Echo (£89.99 / $99) has six'shells' users can swap to customise its appearance. The next generation speaker, which is powered by Amazon's Alexa voice assistant, will have a dedicated woofer and a tweeter for the first time, as well as Dolby sound.

When Siri first hit the scene in 2011 -- as the flagship feature on the iPhone 4s, no less -- it was a novel piece of software to say the least. The early version of Siri wasn't terribly powerful, but it was able to answer relatively basic queries and handle rather simple tasks such as setting reminders. In subsequent updates, Siri became much more powerful, even adding contextual awareness along the way. Equally as important, Siri's ability to parse and understand language improved by leaps and bounds as well. Though Siri's capabilities today are far more advanced than the version that shipped six years ago, it's not as if Apple has the market cornered on AI-powered assistants.

Inspired by news that Vladimir Putin had told Russian students the country that leads in artificial intelligence will rule the world, the Tesla and SpaceX CEO declared the global race to dominate AI might turn into real war--and that the first strike could well be launched by an algorithm rather than a flesh-and-blood leader. Chastised by one of his followers for the gloomy prognostication, he apologized and then confessed, "I was depressing myself too. Musk is a techno-provocateur with few equals. However, plenty of people share his take on AI. Even sunnier forecasts about the future of AI, detailing how self-driving cars might radically reduce highway carnage, are typically too long-range to offer much of a sense of comfort.

At the smaller, cheaper end of the scale, you'll find wee speakers like the Google Home Mini ($49 on Google) and the Amazon Echo Dot ($45 on Amazon). On the higher-quality, more expensive side, several options focus on audio quality and keep the AI assistant's smarts as well. Amazon also offers two more options in this middle category: the bigger, better-sounding Echo Plus ($150 on Amazon) and the smaller Echo Spot ($130 on Amazon), which has a smaller speaker but adds a miniature screen. While these groups offer a general way of categorizing the field of smart speakers, you can also try to determine audio quality by looking at specific features: Check the size and number of internal speakers, including woofers for bass sounds and tweeters for high sounds.

Echo devices keep getting better, getting multi-room audio, access to Google calendars, and intercom features. Now, though, Amazon just matched one of Google Home's killer features: the ability to recognize multiple voices. In a video on the retailer's help site, you can see how to set up and use Voice Profiles. Alexa can now recognize voices in order to route Messages, Calls, allow access to shopping without a confirmation code, play Flash briefings and access an Amazon Music Unlimited Family plan based on the person speaking. To set up your own voice profile, you'll need to go through the Amazon app.

Using this model, we observe three challenges, namely, expanding of the von Neumann architecture; testing and ranking the intelligence quotient of naturally and artificially intelligent systems, including humans, Google, Bing, Baidu, and Siri; and finally, the dividing of artificially intelligent systems into seven grades from robots to Google Brain. The Liu/Shi/Liu paper suggests the average IQ of a six-year-old is 55.5. They also suggest that humans are a "special artificial intelligence system made by nature," due to our ability to create and be creative.

When the first home assistants were announced, I was excited. A device I could wake up with a simple hotword that would answer my questions, set reminders, turn on the TV, and dim the lights, all without me having to get off the couch, sounded fantastic. Amazon's Echo and Echo Dot, Google's Home, and a myriad others, most recently the Home Mini, have invaded our kitchens, living rooms, and bedrooms. Heck, I put one in the bathroom. Without fail, every time a new listening device comes to market, some tinfoil hat-wearer points out how perfect they would be as modern-day Trojan horses for any of the three-letter acronym organizations - NSA, CIA, FBI - you name it.

You might have missed the Apple references during last week's Google Pixel 2 event, but they were there. There was VP or Product Management Mario Queiroz telling the crowd, "We don't set aside better features for the larger devices." Or pointing out that "even iMessages" would be transferred over when you decide to switch. And let's not forget the woman taking a big bite out of an apple during the Pixel 2's intro video. In fact, it seemed like every new Google product released last week had a singular message seemingly aimed squarely at Apple.

I was about to plug my new Google Home Mini into the wall outlet this weekend when I froze. What kind of a commitment was I about to make? Google had handed out freebies of its puck-sized, fabric-coated gizmo at a press event last week. It seemed like a good, low-risk opportunity to dip my toes in the home voice-assistant waters. Scott Rosenberg is an editor at Backchannel.