Heartbeats

Heart rate is the term used to describe the frequency of the cardiac cycle. It is usually calculated as the number of contractions of the heart in one minute. Heart rate is usually measured in "beats per minute" (bpm). The heart rate can increase as a response to a wide variety of conditions in order to increase the cardiac output, the amount of blood ejected by the heart per unit of time. Resting heart rate is a term used to describe a person's heart rate when they are not performing any activities. A person's resting heart rate is likely to increase as they age. Normal rates range from 60 to 80. Fit people generally have a lower resting heart rate; it is often used as a measure of fitness. Exercise causes a normal person's heart rate to increase above the resting heart rate. As the physical activity becomes more vigorous, the heart rate increases more. With vigorous exercise, the maximum heart rate can be reached. Maximum heart rate is the maximum heart rate that a person can achieve during maximal physical exertion. It is most closely linked to a person's age, declining as they age. The speed at which it declines over time is related to fitness - the more fit a person is, the slower the decline.

The pulse is the most straightforward way of measuring the heart rate. Pulse is the throbbing of a person's arteries as an effect of the heart beat. It can be felt at the neck, at the wrist and other places. The pulse results from pressure waves moving through the blood vessels, which are flexible. When the heart contracts, blood is ejected into the aorta causing the aorta to stretch.

The listening process starts with hearing. Beginning at the sixteenth week after conception and continuing until our death, hearing is a constant physical phenomenon. Sound waves are captured by the outer ear, known as the pinna, and travel down the auditory canal, through the eardrum and into the middle ear. There, the vibration of tiny bones called ossicles intensifies sound, and the amplified sound then travels to the inner ear through a maze of fluid-filled tubes, running through the temporal bone of the skull. Eventually the vibrations of sound reach the cochlea, a coiled chamber which is lined with four rows of tiny hair-like acoustic sensor cells containing neurons.

Each neuron is programmed to pick up a different frequency and the sound meets with the neuron that matches its own frequency. The cochlea then converts the vibrational energy to electrical impulses that travel to the brain, and from there, travel to the brain stem. This energy at the brain stem activates the limbic system. It is here that emotional and physical reactions are produced. Sound energy then moves on to the auditory cortex of the brain where the person becomes conscious of the sound and recognize what he or she is hearing.

As the brain comprehends the sounds or in this case the music, the electrical energy released by the neurons creates various frequencies of brain waves. Once through the brain, music in the form of electrical impulses makes its way down the spinal cord causing an impact on the autonomic nervous system. This, in turn, can impact heart rate, pulse, blood pressure, and