The document discusses communication and its definition. Communication is defined as a process of conveying meaning through shared signs and semiotic rules. It involves various skills like listening, observing, speaking and analyzing. Effective listening is also important for communication. There are different listening modes like competitive, passive and active listening. Factors like the speaker, listener and message can influence communication. Language is the main instrument of communication and has oral and written forms. The document then discusses the speech mechanism, including the motor, vibrator, resonators and articulators. It describes the different parameters of voice like quality, pitch, intensity and rate. It also discusses consonants and their place and manner of articulation.