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.
General. The decibel, or dB, is a means of expressing the gain of an active device (such as an amplifier) or the loss in a passive device (such as an attenuator or length of cable). It is simply the ratio of output to input expressed in logarithmic form.The decibel was developed by the telephone company to express the gain or loss in telephone transmission systems, and is best understood by first discussing the rationale for its development.he decibel, or dB, is a means of expressing the gain of an active device (such as an amplifier) or the loss in a passive device (such as an attenuator or length of cable).