Owners of Samsung's Galaxy S9 and Galaxy S9 Plus will soon be able to rely on an alternative method of calling up Google Assistant, provided they haven't already received the option to do so. The feature comes in the form of "Hey Google" trigger word support that's bundled into the latest over-the-air software package Samsung started distributing to its Android flagships earlier this month. The same firmware also ships with the June 2018 Android security patch and a variety of other functionalities and improvements, though carrier-locked Galaxy S9-series devices aren't expected to receive it for at least several more weeks.
The unlocked variants of the two devices should be updated by mid-July, with the Galaxy S9 receiving the software build G960FXXU1BRF8, whereas the one arriving to the Galaxy S9 Plus is identified as the G965FXXU1BRF8. The official changelog of the update explicitly mentions the addition of the "Hey Google function" but doesn't explain how to activate it. The process itself isn't complicated but also isn't obvious, with the only way to enable the new trigger phrase being to retrain your voice model used by Google Assistant for recognizing when you're trying to summon it. To do so, launch the Google Android app, tap the "More" icon in the bottom-right corner of its starting screen, select "Settings," then tap on the "Voice Match" option. The following interface contains a "Retrain voice model" command that you'll have to use in order to enable simultaneous support for both "OK Google" and "Hey Google" hotwords.
In case the service doesn't ask you to say "Hey Google" out loud, check whether you're running the security patch dated June 1, 2018. If you aren't the new feature has yet to arrive to your handset. If you are, try clearing the Google app's cache or reinstall it entirely. The latest Galaxy S9 firmware from Samsung also adds a number of disclosures and controls meant to ensure compliance with the recently introduced General Data Protection Regulation in Europe.