Image caption Amazon's Alexa director Daren Gill has called voice "the next great interface"

For the last four weeks, I've been living in an Orwellian nightmare. One in which I have to watch every word I say because "they" are always listening. And by "they", I mean Alexa, Siri and Google.

It seemed like a good idea - get seven smart speakers and test them in a real house to see how they affected our listening habits and daily routine.

At times, they've been pretty helpful. If we're running low on biscuits, one of us can bark, "Hey Siri, add Hob Nobs to the shopping list" and a reminder appears on our phones.

During Storm Emma, Google kept me up-to-date on train cancellations, while our kids amused themselves for hours by asking Alexa what noise a cat makes.

Thankfully, none of the devices started spontaneously laughing in the middle of the night - but they were all prone to bouts of madness.

I once asked Alexa "what's the weather in Yemen" and got the reply: "'Das wetter' is German for 'the weather'."

And when I told Google to "play music in the kitchen", it responded by streaming Lee Brice's Songs In The Kitchen to a speaker in the dining room (congratulations, Lee, on your new royalty stream).

To find out which smart assistant was the smartest, I put each of the speakers to the test - posing 50 random questions on music, sport and general knowledge. Like all good quiz show hosts, I only accepted their first answer.

Alexa fared best, with 37 correct answers, followed by Google on 32, and Siri, which scored a lowly 27.

Apple's assistant was hobbled by its lack of integration with other apps - meaning it couldn't read my calendar or look up recipes.

When it came to music-related queries, however, Siri had more success.

For instance, the HomePod was the only speaker that could parse the command "play the James Bond theme next". Its competitors all tried to find a song called "James Bond Theme Next", failed, and gave up.

You can find the full list of questions, and how the speakers responded, here.

None of them are perfect (never ask for music by Haim in a Northern Irish accent) but smart speakers look set to replace the smartphone as the tech giants' biggest growth products.

Choosing the right one can be tricky. So here's our guide to the speakers, and how they might fit into your lifestyle.

Apple HomePod (£319)

Image copyright Apple

Apple has arrived late to the smart speaker market, but not through laziness.

The HomePod has been in development since 2012, and boasts an unconventional design - with seven tweeters (the speakers that produce treble) arranged in a circle to project music into every nook and cranny of your house. The bass is also punchy and well-balanced, even at low volumes.

I found it worked better with acoustic, singer-songwriter material. Playing Regina Spektor's Samson, the HomePod championed the singer's vocals without losing the detail in her piano work. On a busier song like Stevie Wonder's Superstition, however, it struggled to pick out the star's intricate drumming.

It's also an incredibly insistent speaker - demanding your attention with a very "forward" soundstage. We found that was great in the hustle and bustle of a family kitchen, but less attractive when listening to music in bed at night.

One important note: You can't set up the HomePod unless you have an iPhone or an iPad. The speaker is then tethered to that device and certain functions, like updating your shopping list, only work when they can "see" each other.

HomePod is also completely loyal to Apple Music. You can't ask Siri to stream from Spotify or Deezer - although you can access them on your phone and beam them to the speaker. That process can be fiddly, though, and connecting to the speakers via Apple's proprietary AirPlay technology is much slower than pairing your phone with a bluetooth device.

Update - October 2018: A new software update means you can pair two HomePods and listen in stereo. The improvement in sound quality is noticeable and impressive, although the speakers I tested sometimes fell out of sync.

Best for: Apple enthusiasts; audiophiles

Amazon Echo Plus (£139)

Image copyright Amazon

If you want a speaker that comes with a free light bulb, then Amazon's Echo Plus is your only choice.

The speaker aims to be a "home hub", controlling all sorts of connected devices, from your lights to your kettle. I wasn't able to test those abilities, though, as the BBC budget didn't stretch to buying me remote control curtains.

As a music player, the Echo Plus is competent but unspectacular - but it'd make an ideal replacement for a kitchen radio.

Alexa will happily stream from Spotify and Deezer, as well as Amazon's own Music Unlimited service - which you get at a discount if you purchase an Echo device.

It's particularly good at finding the music you want, even if you have a terrible memory. I managed to get Alexa to cue up Girls Aloud's Love Machine by asking, "What's the song that goes, 'Let's go, Eskimo?'"

One word of warning: Amazon's streaming service doesn't have a parental filter, so you're stuck with the explicit versions of the songs in their catalogue.

And now that Amazon has leased Alexa to other speaker manufacturers, there are better devices in a similar price range.

Best for: Casual listening, smart assistant abilities

Ultimate Ears Megablast (£199)

Image copyright Ultimate Ears

The Megablast is a long, tall cylinder of fun, available in a range of colours (our review unit was a lurid yellow, which I became weirdly fond of).

It gives out a bassy, fulsome sound; which goes up really, really loud without losing any finesse. You can use Alexa to play songs from Amazon Music Unlimited (but not Spotify yet), or simply use it as a bluetooth speaker to stream music directly from your phone.

Best of all, you can unplug it and take it to a party, with a generous battery life that means you won't be left tuneless when the clock strikes midnight. And it's waterproof, so it won't go kaput if you spill your drink.

On the downside, the microphone is poor at picking up your voice commands - especially when music is playing. And the charging port is awkwardly placed at the bottom of the speaker, meaning it has to be laid on its side when its plugged in, ruining the sound. (Ultimate Ears sells a separate charging dock, pictured above, for £35 if this is a deal-breaker).

Best for: Portability, volume

Sonos: One (£199)

Image copyright Sonos

Sonos are masters of multi-room audio, but the One is their first foray into smart speaker territory.

There's an intriguing set-up, where you're asked to wave your phone around the room while the unit emits a series of sci-fi bleeps and bloops.

This helps the speaker adapt to its environment and, to be fair, it performed admirably in our cluttered bedroom, with a weighty, dynamic delivery that belied its tiny size.

Superstition, which confounded Apple's HomePod, sounded bright and lively, with a deep, funky bass and plenty of breathing room for Stevie Wonder's vocals.

Best of all, Sonos welcomes all music streaming services - with 49 currently available in the UK, including Apple Music (not all of them can be controlled by Alexa, though).

You can also chain two Sonos speakers together to get stereo, while the Sonos app is the only one that allows you to tweak settings like treble and bass to tailor the music to your tastes. And if you buy multiple units, you can scare your family by playing ghost noises in the attic while you're in the kitchen.

One small niggle: Sonos has programmed Alexa to speak over the start of your music, so you constantly miss the first five seconds of your favourite album.

Best for: Stereo, choice of streaming services, multi-room audio

Google Home (£129)

Image copyright Google

It looks like an air freshener. An air freshener on the Starship Enterprise, but an air freshener nonetheless.

Still, I was quite enamoured with the Home's sleek, matte white finish and the easygoing, friendly voice of its virtual assistant.

It transpires that her dialogue was written by Emma Coats, a former Pixar employee who drew up the film studio's 22 rules of storytelling - which explains why Google feels more engaging than its competitors.

There are a few neat touches to the AI, too. When you ask Google to "flip a coin", for example, you hear the sound of a coin being tossed before learning the result. Even better, the Google Home enables you to make voice calls to any UK landline or mobile number - for free.

Sadly, though, the device isn't up to much as an actual speaker. It had the worst sound of all the units we tested, and was prone to distorted bass even at low volumes.

Best for: Personality, design

JBL Link 300 (£249)

Image copyright Harmon Kardon

Luckily, fans of Google's voice assistant have some alternatives. Sonos are promising a Google-enabled speaker later this year and JBL will release their Link 300 in the next couple of weeks.

It's a chunky little device that works best on pop and hip-hop, with an eloquent sound that emphasises the low end thanks to a circular resonator on the back that pumps out the bass.

One neat feature is a wi-fi light that shows the strength of your internet connection (something I'd like to see on more devices, given the patchy wi-fi in our house).

In the end, this became our go-to speaker in the living room and kitchen, despite an infuriating five-minute fight to make it play the Hamilton soundtrack.

It turns out you had to say "OK Google, play 'Hamilton: Original Broadway Cast Recording'" - a command that's as intuitive as a lead wetsuit.

Best for: Google smarts with better sound.

Amazon Echo Show (£199)

Image copyright Amazon

The Echo Show has a 7-inch screen, which displays song lyrics while you listen. It's a bit of a gimmick, but it was a big hit with our kids.

The device also came in handy in the kitchen, where we used it to display recipes and set timers without having to touch the screen with our sticky fingers.

All this functionality comes at the cost of sound quality, though. Don't expect anything beyond your average clock radio.

Best for: Karaoke night

Secret option eight: Don't buy any of them

Image copyright Getty Images

Here's the thing: With the possible exception of Sonos: One, you're not getting true hi-fi sound with any of these devices.

If you've already got a good home stereo, it's much cheaper to buy an Amazon Echo Dot (currently £39) and hook it up to your existing set-up with a simple cable.

Similarly, if you've got £300 to spend, you can get a decent hi-fi system and an Echo Dot with money to spare.

That way, you get all the benefits of voice control and music streaming without breaking the bank.

Best for: People who've already got speakers and have privacy concerns about this whole thing.

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