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.
7.1 Structure of the Ear and Pitch Perception. Parts of the ear: Ear lobe - concentrates high frequencies, gives sense of direction. Animals control ear lobes. Ear canal - open-closed resonator, enhances frequencies around its fundamental resonance, which is in the range of 2000 â 5000 Hz. Resonant frequency used to determine length of canal for fitting hearing aids. Ear drum - converts sounds waves to mechanical vibrations, much like a microphone. Inner ear bones - transfers mechanical energy to oval window on cochlea. Protects against loud noises. Cochlea - fluid filled canal with Basilar membrane running along its length.