voice of reason

:  sound produced by vertebrates by means of lungs, larynx, or syrinx

:  sound so produced by human beings

:  musical sound produced by the vocal folds and resonated by the cavities of head and throat

:  to express in words :  utter

:  to adjust for producing the proper musical sounds

:  to pronounce (a speech sound, such as a consonant) with voice

:  a statement offered in explanation or justification

:  a rational ground or motive

:  a sufficient ground of explanation or of logical defense

:  to take part in conversation, discussion, or argument

:  to talk with another so as to influence actions or opinions

:  to use the faculty of reason so as to arrive at conclusions