Nonverbal communication is the transmission of messages or signals through a nonverbal platform such as eye contact (oculesics), body language (kinesics), social distance (proxemics), touch (haptics), voice (prosody and paralanguage), physical environments/appearance, and use of objects. When communicating, nonverbal channels are utilized as means to convey different messages or signals, whereas others interpret these messages. The study of nonverbal communication started in 1872 with the publication of The Expression of the Emotions in Man and Animals by Charles Darwin. Darwin began to study nonverbal communication as he noticed the interactions between animals such as lions, tigers, dogs etc. and realized they also communicated by gestures and expressions. For the first time, nonverbal communication was studied and its relevance noted. Today, scholars argue that nonverbal communication can convey more meaning than verbal communication.
In the same way that speech incorporates nonverbal components, collectively referred to as paralanguage and encompassing voice quality, rate, pitch, loudness, and speaking style, nonverbal communication also encompasses facets of one's voice. Elements such as tone, inflection, emphasis, and other vocal characteristics contribute significantly to nonverbal communication, adding layers of meaning and nuance to the conveyed message. However, much of the study of nonverbal communication has focused on interaction between individuals, where it can be classified into three principal areas: environmental conditions where communication takes place, physical characteristics of the communicators, and behaviors of communicators during interaction.