How to delete you voice recordings because Google is listening
Google and Amazon have both admitted that they have hired contractors that listen to anonymized user audio clips. The purpose, according to the companies, is to improve Google Home ($99 at Walmart) and Amazon Alexa, respectively. Certain aspects of Google's platform centers around personalization, whether it be in news search results, music, maps, etc. Much of that information is gleaned from listening to what people want to know.
You can find all of your activity (depending on the settings of your phone) if you look hard enough. Most easily, probably, who you called and who called you. Go deep enough into Google Maps and you're movements are tracked. Google Home is no different. Everything you say to the smart speaker or Google Assistant is stored in the My Activity section of your Google account. You can read a list in the Google Home app or actually listen to your own voice if you explore on PC or mobile browser.
It might seem like you only have two options -- use the internet and forfeit your data or go off the grid to protect your privacy. Having an attitude like Ron Swanson from Parks and Recreation isn't practical and there isn't a foolproof privacy solution if you're active on the internet.
Fortunately, you can purge your account of all these recordings rather easily.
Delete your Google Assistant voice recordings on your PC
Delete your Google Assistant voice recordings on your phone
Unfortunately, the ability to filter by date and product isn't available in the Google Home app yet. You can only filter date, so you either have to delete commands one at a time, delete everything or your web activity gets lumped in. It works on mobile browser though.
From here, whether on PC or mobile, you can delete individual recordings or entire days of activity. If you click your tap the three-dot settings in the search bar, you can itemize what you want to delete by month or request. (i.e. everything you said to Google in July or just when you asked Google to turn on the lights) You can also interact directly with months and items to delete them by tapping or clicking the three-dot settings icon.
You can also delete your voice history by searching a specific date (instead of scrolling forever) or a date range.
You can do the same thing on mobile:
How to turn off Voice & Audio Activity
You can stop Google from saving your voice recordings and audio activity to your account under Activity controls in your Google account settings. However, it will cause voice searching with Google Assistant (including Google Home speakers) to stop working until you re-enable it.
Here's how to do it on PC:
Here's how to do it on the mobile app (you can also follow the PC steps and do it on mobile browser):