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: My trusty Etymotic ER-6 noise-isolating earbud headphones. These work by passive noise cancelling: each earpiece has a pair of (washable) plastic suction cups that make a tight seal in your ear canal to stop noise getting in and music leaking out. If you prefer, you can pull off the plastic cups and use disposable, soft foam ones instead.