I notice that many honorifics have similar consonant sounds when spoken. For example, the ~ㅂ/습니다 conjugation and the ~님 noun ending (e.g., in 선생님, 사장님, 아버님) have the ㄴ and ㅁ sounds when spoken.
Are some sounds more pleasing to the ear? Indeed to me the ㄴ and ㅁ consonants sound like honey, but could that be why the Korean language evolved this way - people spoke to their elders and rulers with sweeter tones and more agreeable melodies?
The ~ㅂ/습니다 conjugation could have been the ~ㄹ/즐보다 conjugation or something else, but perhaps that sounds less exalted or melodic.
I’m looking for psychological/neurological/linguistic research about these topics - please don’t speculate as an answer. Thanks!