Hear a sound after saying “Ok Google” on Google Home device

When Google Home hears the hotword (“OK Google” or “Hey Google”), it records what you say and sends the recording to Google to fulfill your request.

To hear a brief sound at the start and/or end of your request:

1. Make sure your mobile device or tablet is connected to the same Wi-Fi as your Google Home device.
2. Open the Google Home app .
3. Scroll down until you find the device you would like to control.
4. Tap the device.
5. In the top right corner of the device card, tap Settings .
6. Scroll down to device info.
7. Tap Accessibility.

8. If you want to hear a sound only after saying “OK Google” turn on the toggle next to Play start sound  and leave the Play end sound slider off .

9. If you want to hear a sound after Google Home after saying “OK Google” and after Assistant stops listening, turn on the toggle next to Play start sound and Play end sound 

via Google help