The Trick That'll Make Voice Chat Easier On The Nintendo Switch
There are a lot of reasons why so many people enjoy the Nintendo Switch despite the hardware being a little bit behind the curve compared to its competitors. However, the console's comparably limited online functionality isn't usually one of them. Sure, you can play Switch games over the internet and stream older console games if you subscribe to the Switch Online service, but voice chat is another matter entirely.
If you want to talk with friends, teammates, or rivals while playing games on your Switch, you basically have two options: Play a game that specifically supports voice chat, like "Mario Kart 8 Deluxe" or "Splatoon 2," or use the Nintendo Switch Online app as a sort of go-between (which is basically like calling someone on the phone via messaging app).
The downside to this particular method being that headset users have to choose between hearing voice chat with no game audio (because it isn't piped through the headphones), or not bothering with chat in the first place. However, there's also a secret third option that will allow you to use a headset to chat, as well as listen to in-game audio — kind of. It's not so much a secret; rather it's a technological workaround that relies on the capabilities of the headset you're using.
Here's the trick
Getting your Switch's voice chat to behave a bit more like what you might be used to on other modern platforms is pretty simple, but it requires a little bit of research. You'll also still need to use the Nintendo Switch Online app to facilitate chatting with folks. Basically, you'll want to get yourself a pair of headphones (or earbuds) that supports "dual wireless" functionality.
It's possible you already own a set that does this, but if not you'll want to try and find a pair that advertises multi-device (sometimes called multipoint), pairing so it can connect to more than one device at a time, as well as dual wireless. The set needs to include a microphone, of course; something like the Corsair HS70 or SteelSeries Arctis 9 should do the trick.
Once you have the right headset, you just have to pair it with your smartphone and the Switch. You'll then be able to hear your Switch's audio, in addition to the audio from your phone — which includes voice chatting through the Nintendo Switch Online app. It's certainly not as elegant a solution as console voice chat, and it requires a bit of legwork (and possibly extra expenses), but it's functionally the same as what you'll find on a computer, PlayStation, or Xbox.