Threadmill - remove audio prompts about pace when doing workout?

Hi

When I am doing a daily suggested workout on the threadmill I want to turn off the audio prompts about pace. The threadmill measurement is too inaccurate - despite having calibrated multiple times and fluctuates easily between e.g 7:40 and 5:40 at a 6:40 run pace on the threadmill. This gives a lot of audio prompts about "too fast/too slow/in zone" which can drive you bonkers. 

Now I *want* those warnings if I run with a run/race workout as they are outdoors where the GPS is fairly accurate.

Can I turn them off for each activity? 
It seems to be a global setting (audio prompts for workouts yes/no).