Internal monologue, also known as inner voice, internal speech, or verbal stream of consciousness is thinking in words. It also refers to the semi-constant internal monologue some people have with themselves at a conscious or semi-conscious level (see Default mode network). Much of what people consciously report "thinking about" may be thought of as an internal monologue, a conversation with oneself. Some of this can be considered as speech rehearsal.
When reading, some people's internal monologue moves their muscles slightly as if they were speaking; this is called subvocalizing.
In some medical or mental conditions, there is uncertainty about the source of internal sentences. Attribution for an internal monologue may lead to concerns over schizophrenia, hallucinations, or hearing voices. This internal monologue is stimulated by the sensory parts of the brain, activating both auditory and visual receptors.
Contemplation "attempts to calm the internal voice" by various means.
In the philosophical field of language there is much research about internal speech in correlation with the building and usage of phrases in one's own idiom and thus the importance of language in the process of thinking.
