You’ll need to change the system volume on your device (usually located on the side).
The ability to change the volume was possible in the iPlayer Radio app, but as changing volume was overwhelmingly done using controls outside of the app, we have not included this feature in the BBC Sounds app.
If using Chromecast, you can still change the volume using the volume controls outside of the app. We're aware of an issue with changing the volume from an iPhone or iPad when casting and we'll update this page when we have any further information.