You have few options:

1. You can shoot a heavier arrow which absorb more of energy on the shot (kinda expensive).

2. You could look into the option of a string supressor. HNI's own MeanV makes a custom string supressor:

http://www.meanvarchery.com/index.html

3. Google and download the 'Easton Tuning Guide'. A well tuned bow will shoot quieter. Some of the info is a bit dated and some will debate the value of paper tuning. However, this guide is a good place to start learning about tuning.

4. It's best to have friend help evaluate your bow noise level because it always sounds louder to the shooter.

5. Congrats on your harvest.