Chromecast Audio uses sounds to indicate user actions. Here's more on how you can customize playback sounds:
Playback sounds
Start of cast session
Whenever you start a cast session, Chromecast Audio will play a playful sound in order to indicate a connection was made and playback is about to start. You can also use this time to adjust the volume to your preferred levels before the music starts.
Tip: The time it takes before music playback actually starts depends on the app you're using for casting.
Volume change
When changing the volume of your Chromecast Audio through the music app or your Google Home app, your Chromecast Audio will play a short sound confirming a volume change was done.
Turn off playback sounds
- Make sure your phone or tablet is on the same Wi-Fi or signed in to the same account as your Google streaming device.
- Open the Google Home app
.
- Tap Home
All devices
, then touch and hold your device's tile.
- At the top right, tap Settings
- Turn off Playback sounds.
All devices 
Full Dynamic range
Chromecast Audio supports Full Dynamic range output. This provides premium and professional audio equipment such as Hi-Fi audio systems, AV receivers, and monitor style speakers with the highest quality sound output.
Turn on Chromecast Audio’s Full Dynamic range option when you connect to such sound systems with a 3.5 mm or RCA analog cable:
- Make sure your phone or tablet is on the same Wi-Fi or signed in to the same account as your Google streaming device.
- Open the Google Home app
- Tap Home
- At the top right, tap Settings
- Turn on Full Dynamic range.
Many common speaker systems like desktop computer speakers, docking speakers, portable and Bluetooth speakers aren't built to support such a Full Dynamic range. This causes very loud volume levels and distorted sound. Avoid turning this setting on in those cases.
When Chromecast Audio is connected through an optical interface, it'll always use Full Dynamic range. Setting Full Dynamic range to off won't have an effect as it'll remain on.