This is a ringing that sets in after excessive noise exposure, such as in a rock concert (being too near the speakers) or the explosion of a firecracker. This excessive noise can cause injury to the ear, causing the ringing. The tinnitus will usually clear up on its own, and will last anywhere from minutes to hours.
Mechanical digestion is the actual physical break down of food into smaller pieces. One example of this is mastication (chewing) which occurs in the mouth by the teeth, which act to cut and grind food into smaller pieces. This makes them easier to later digest as it increases the SA of the food molecules.
The difference between chemical and mechanical digestion is:    Simple:   Chemical digestion= Process that breaks large food parts  into small molecules that can b â¦ e taken in by cells.   Mechanical digestion= Process of breaking down food into  smaller pieces by chewing and smashing.   More advanced:   Mechanical Digestion-Food is crushed and liquefied by the  teeth, tongue, and peristaltic contractions (waves of involuntary  muscle contraction) of the stomach and small intestine. Mechanical digestion= Process of breaking down food into  smaller pieces by chewing and smashing.    More advanced:   Mechanical Digestion-Food is crushed and liquefied by the  teeth, tongue, and peristaltic contractions (waves of involuntary  muscle contraction) of the stomach and small intestine.