Which of the following is not an example of a nonverbal signal?

The volume of voice is considered a verbal signal rather than a nonverbal one. While it can convey emotions and emphasize certain aspects of spoken communication, it involves modifying speech rather than expressing meaning without words. In contrast, facial expressions, body language, and hand gestures all operate independently of spoken language and communicate feelings, attitudes, or reactions nonverbally. Each of these elements plays a crucial role in interpersonal communication by conveying messages through physical cues instead of verbal ones. Thus, volume, which pertains to the auditory aspect of communication, does not fit the definition of a nonverbal signal.