You can adjust the volume and duration of the Thermomix® TM5 warning tone, but it cannot be turned off completely for safety reasons. To stop the tone, either reduce the speed using the selector or press the selector directly.
Removing the mixing bowl also stops the tone. Note that a recent software update has unified the tone for ending "automatic recipes" with the standard tone, unlike earlier versions which had a different tone.
If you need further assistance, please contact us at https://service.thermomix.com/hc/en-us/requests/new. Our Customer Happiness agents will get back to you in 1-2 business days.