Oral communication refers to any interaction that uses spoken words and occurs in two main forms: face-to-face communication and communication using mechanical devices. Face-to-face communication involves direct interaction between participants in the same physical space and is still considered the best form because it allows for emotional engagement, assessment of trustworthiness, and an exchange of energy. Common mechanical devices for oral communication include signals, speaking tubes, dictation machines, intercoms, and telephones/cell phones.