Speech is a verbal means of communicating or conveying ideas and sharing feelings. It is the audible form of language. By complex processes in the brain, a speaker converts an idea in his mind into a stream of sounds, moving his lips, tongue, jaws in swift precise gestures; he transmits information in orderly audible units.
The speech mechanism is carried out at various levels in our body. The following systems are involved:
- Speech Encoding areas in the Brain
- Lungs and the respiratory muscles
- Larynx ( Voice Box in the throat)
- Vocal Tract
- Mouth with its different parts or articulators ( tongue, teeth, lips, palate)
Speech is also defined as modified air flow. The air from the lungs sets the vocal cords in vibration which produces sound in the larynx (voice box). This air resonates in the vocal tract and the pharynx and is acted upon by the articulators in the mouth to form speech units (phonemes). The cortex in the brain is largely responsible for the neuromuscular coordination of all these complex processes that are involved in speaking. When a child learns to speak, these processes are slow and hence there is a developmental progression in which a child learns to first coo, goo, then babble, then learn words and later strings these words them into complex sentences and starts conversing like adults.
For better understanding, speech has been said to have the following components –
- Voice – This is the sound produced by the vocal cords in the larynx ( voice box)
- Articulation – This is the act of speech production in the mouth. The different oral articulators ( parts of the mouth) aid in this process. The palate, tongue, teeth and lips all work in unison to produce speech)
- Fluency – The uninterrupted, continuous forward flow of speech is called fluency.
- Prosody – This is the study of tune, rhythm and stress patterns in speech. These segments tend to change the meaning in which speech is directed to the listener.