Definition: Sibilance is a sound characterized by pronouncing words with the letter 's'. In audio reproduction the letter 's' should sound clear and distinct, not smeared or distorted as in 'sh'.
High air pollution levels can cause immediate health problems including: Aggravated cardiovascular and respiratory illness; Added stress to heart and lungs, which must work harder to supply the body with oxygen; Damaged cells in the respiratory system
Abnormal breath sounds are usually indicators of problems within the lungs or airways. The most common causes of abnormal breath sounds are: 1  pneumonia. 2  fluid in the lungs. 3  heart failure. 4  abnormally thick chest wall. 5  reduced airflow. 6  emphysema. 7  asthma. 8  bronchitis. 9  lung disease. 10  foreign body in the lungs or airways.