LIN228H1 Chapter Notes - Chapter 13: Egressive Sound, Ingressive Sound, Vocal Tract
Document Summary
Boyle"s law: pressure of gas varies inversely with volume; if possible, gas will move to equalize different pressures. In speech production, the air pressure in lungs can change. If oral/nasal passage is open, air moves in and out. Primary air stream mechanism for speech, with lungs as initiator. All english sounds are pulmonic; most languages use only pulmonic egressive sounds; great majority of sounds are pulmonic egressive. Anatomy: bronchus (pl. bronchi) are tubes, one for each lung, joining at the trachea (ring of cartilages, external intercostals lift rib cage up to hold/inflate lungs; also known as ingressive muscles. Internal intercostals pull rib cage down to deflate lungs; also helped by abdominal muscles; also known as egressive muscles. Pulmonic egressive sounds are created when chest cavity contracts so that subglottal pressure is greater than outside air pressure. Increase in air pressure in pharynx and oral cavity: air rushes out until air pressure inside vocal tract equals outside air pressure.
