Audio quality. is terrible

You need to go here for Spark help https://adobespark.zendesk.com/hc/en-us/categories/202688167-Adobe-Spark
-the above link has a full page of over 90 links for help articles
-also https://community.adobe.com/t5/get-started/adobe-spark-helpful-resources/td-p/11003736?page=1
-also https://fonts.adobe.com/collections/spark-font-pack
-also https://blog.adobespark.com/2019/06/10/stand-out-with-sparks-new-premium-templates/

This is the poorly named Community Help forum (which is the forum for issues using the forums).
Please tell us what Adobe application you are using so that this can be moved to the proper forum for help.