No, a Pause object will pause everything so the image and audio cannot be paused separately.
However, if you are using the Pro edition, instead of inserting a Pause object, you could insert duplicate frames from the length of time that you want the movie to appear paused for:
- Select the frame that you want to duplicate to simulate a pause
- Disable editing for the audio track by clicking on the title box (the red highlight will disappear when the track is disabled for editing)
- Right click on the selected frame and click the Insert Frame(s)... option.
- Enter the length of time (in seconds) that the movie image should pause for