http://www.wired.com/2016/08/review-garmin-virb-ultra-30/?mbid=social_fb#slide-1

Garmin specially designed a mic port for the waterproof case, and
you may not believe it, but the sound is just as clear with the case on as it is
with the case off. It’s totally unprecedented in the arena of action cams, and
its audio quality blows the doors off everything else.

Another terrific idea Garmin has implemented is voice control. You alert it by
saying “OK Garmin…” and then “start recording,” “stop recording,” “take a
photo,” or “remember that” (to add a tag to that part of the video).

Armin makes wearable sensor tech of all sorts, so it makes sense that the new
Ultra 30 packs a GPS radio, a barometer (for elevation), an accelerometer (for
force and motion), a gyroscope (for rotation), and a compass (for bearing). All
of that data can be overlayed onto your video (if you use Garmin’s app or
desktop editing software).

This advantage is extended further because the Virb also has Wi-Fi, Bluetooth,
and ANT+, which means it can pair with dozens of external sensors that Garmin
either makes or works with.