When we think of antonyms for the phrase "more rattling," words like "less" or "quieter" may come to mind. However, there are a plethora of alternative antonyms to consider. For instance, the sound of something being "more rattling" could be countered by a "gentle" or "soothing" sound. Furthermore, "peaceful" or "calm" may work as well, as they convey the opposite of the jarring nature of the phrase in question. As with many words and phrases, the antonyms for "more rattling" depend on context and the speaker's intended meaning. Regardless, expanding our vocabulary with antonyms is a great way to improve our overall communication skills.