Quick Answer. The amount of time it takes for a sound wave to reach the brain is a changing value. The distance of the location from where the sound originates and the type of media the sound travels through are direct factors. Keep Learning.
1 The blood tests most frequently used for liver disease are the aminotransferases (alanine aminotransferase or ALT and aspartate aminotransferase or AST). 2  Normal levels of ALT ranges from about 7-56 units/liter, and 10-40units/liters for AST. Many drugs may cause elevated AST, and ALT and some medications can cause severe damage (for example, acetaminophen [ Tylenol liver damage]). 2  Less common causes of abnormal AST and ALT levels are wide ranging (for example, toxins, and autoimmune diseases).
Liver Enzymes. AST â (aspartate aminotransferase), which was previously called SGOT. This enzyme can also be elevated in heart and muscular diseases and is not liver specific. Normal range of AST is 5-45 U/L. ALT â (alanine aminotransferase), which was previously called SGPT and is more specific for liver damage. Normal range of ALT is 5-45 U/L.