For which of the following reasons might a sound technician speed up a section of audio?

to maybe change the way the sound of that section "sounds", speeding up is usual on ly when you want something to sound high pitched!

to create a sense of urgency

Explanation:

The faster a voice is, the more intrigued you are going to be. Based on the speed, you will have to be very attentive to hear what the characters are saying. It keeps you on the edge of your seat, hence why filmmakers use this tactic.