1 Costochondritis. 2  In this condition, the cartilage of your rib cage, particularly the cartilage that joins your ribs to your breastbone, becomes inflamed and painful. 3  Sore muscles. 4  Chronic pain syndromes, such as fibromyalgia, can produce persistent muscle-related chest pain. In this condition, the cartilage of your rib cage, particularly the cartilage that joins your ribs to your breastbone, becomes inflamed and painful. 2  Sore muscles. 3  Chronic pain syndromes, such as fibromyalgia, can produce persistent muscle-related chest pain.
For other uses, see Decibel (disambiguation). The decibel (dB) is a logarithmic unit used to express the ratio of two values of a physical quantity. One of these values is often a standard reference value, in which case the decibel is used to express the level of the other value relative to this reference.
Bibliography (from Greek Î²Î¹Î²Î»Î¹Î¿Î³ÏÎ±ÏÎ¯Î± bibliographia, literally book writing), as a discipline, is traditionally the academic study of books as physical, cultural objects; in this sense, it is also known as bibliology (from Greek -Î»Î¿Î³Î¯Î±, -logia).