soft-spo·ken /-ˈspokən/
  (a.)說話溫和可親的,溫和地說話的,善於言辭的
  Soft-spo·ken a. Speaking softly; having a mild or gentle voice; hence, mild; affable.
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  soft-spoken
       adj : having a speaking manner that is not loud or harsh; "she was
             always soft-spoken"