Quick Answer. Cardiotonic drugs are substances that increase the contracting mechanism within the heart, thereby causing more blood to be pumped throughout the circulatory system. These drugs usually affect intracellular calcium levels in the heart muscle to achieve the desired increase in muscle action.
Like the name suggests, the entire CIC hearing aid fits into the ear canal. There is nothing on the outside of the ear, making it virtually unnoticeable. The CIC hearing aid is custom-made to fit into your ear canal to ensure a perfect fit.
Photo by Erica Joy. Earbuds and in-ear headphones are tiny earpieces that go inside your ears. You're probably familiar with these, as cheaper earbuds often come with music players (like the iPod). Earbuds generally sit in the bowls of your ears, while in-ear variants actually go in the ear canal, some fairly deeply.