You can switch off programme recommendations (which are based on what you've listened to) by switching off personalisation altogether in your BBC account settings. For more information on how to do this, visit the Using the BBC website.
Bear in mind, switching off personalisation will also switch off the ability for BBC Sounds to remember how far through a programme you are so you can pick up where you left off. It will also remove personalisation within BBC iPlayer, which you can read about here: Personalisation in BBC iPlayer.
It may take a little while for any changes you make to come into effect, but you can speed things up by signing out of your BBC account and signing back in again on all the devices you're signed in on.