The atrial tone, also known as the IV tone, is an important element of communication that helps establish and maintain contact with the interlocutor. It is one of the six tones that are used in the language.
The atrial tone conveys information about the mood, feelings and emotions of the speaker. This tone can be either soft or hard, depending on what the speaker wants to convey. The atrial tone is usually used to express gratitude, sympathy, recognition, explanation, agreement, apology