What version of Premiere Elements and on what computer operating system?
In the absence of that information, I will generalize.
If you want one sound to dominate over the other automatically, then consider the Smart Mix feature where you can
set a "foreground" and "background"
Use the program's audio mixer feature.
Please review the Adobe document on volume adjustments
With more details of Premiere Elements version and other, we can customize a reply.
Please do not hesitate to ask questions and to ask for clarification.
I worked it out! I realised I had to adjust the sound on each part of my clip.#Thanks!
Wonderful news of your success. Great job sorting through the troubleshooting.
Your follow up report on the outcome is appreciated by all.