Topic-091: Pulmonic Airstream Mechanism Pulmonic airstream mechanism is the most commonly used mechanism for speech production by human beings. Almost all the sounds we produce in speaking are created with the help of air compressed by the lungs. The adjective used for this lung-created airstream is ‘pulmonic’: the pulmonic airstream maybe ingressive (as in breathing in) but for speaking practically, it is always egressive (speech sounds are produced while pushing the air out. In order to understand this mechanism, we’ll have to analyze the human respiratory system. Under this system, the respiratory muscles set the air in motion. Lungs – the sponge like tissues – contained within air cage called the diaphragm – contract and enlarge lung cavity thus creating the egressive – ingressive actions. This mechanism set an airflow for speech production and human beings produce speech sounds while pushing the air out.