How do I adjust Speed without changing my voice?

Currently, it isn't possible to change the speed of your video without changing the pitch of your voice. However, here's a possible workaround: 

1. Open your Splice project.
2. On the timeline, tap on your video: it turns blue.
3. Tap on Extract from the editing toolbar. Your audio will now be placed under the video. 
4. Tap on your video again.
5. Tap on Speed from the editing toolbar to adjust the speed using the slider under the timeline.