Google tracks a lot of information about what you've done, which it uses to make suggestions for products like Google Now and autocomplete. Google recently updated its Account History page with the ability to view or pause or voice search history, as well as other information from your mobile devices.
We've covered Google's Account History page before, but Google always adds new features. The updated dashboard lets you selectively remove, turn off, or pause Google history with voice searches and commands from other devices like your tablet or phone.
Even if you aren't too concerned about privacy, you might check it out. If someone borrowed your mobile device or computer, there might be stuff in the history you'd like to remove from that history. Click "Manage history" and delete the stuff you don't want seen.
Google's Web & App Activity [Google Operating System]