Along with sight, hearing is one of man's most important senses. We use it to communicate, learn, and stay aware of our environment. In fact, hearing is the only sense that never stops receiving sensory input. While all our other senses become drastically less sensitive when we sleep, our brain still processes auditory information to wake us up the moment something is wrong. While this may have been used more practically before people slept safely in homes, it is still useful for hearing the fire alarm or alarm clock in the morning. We are able to hear by processing sound waves. This energy travels through the delicate structures of our ears to be transformed into neural activity so that we can perceive the sensory information we receive (Myers, 2010). Each of the senses receives a different stimulus that allows us to perceive that specific type of information. For hearing, the stimulus is sound waves. These are pressure waves conducted through a medium (Martini, 2009). This medium is often air but can also be water or a solid object. Each wave consists of a region in which the air molecules are collected and an opposite region in which they are further apart (Martini, 2009). A wavelength is the distance between two peaks or two valleys of the wave. The number of waves passing through a fixed reference point in a given time is the frequency. High-pitched sounds have a high frequency while low-pitched sounds have a low frequency (Myers, 2010). Amplitude is the amount of energy, or intensity, in a sound wave. The more energy a sound wave has, the louder it seems. In order to perceive the sound waves around us, they must pass through the outer, central and inner areas... the center of the paper... the information is then interpreted and we listen. The range of our hearing abilities is astonishing. Most of this can be attributed to the sensitivity of our hair cells which can detect the smallest audible sounds while enduring a trillion-fold increase in power (Martini, 2009). Our hair cells are constantly changing to adapt to our environment. We can converse with our friends, listen to music, and distinguish which direction a car alarm is coming from without any awareness of the detailed process required for hearing. Overall, the process of transforming sound waves into auditory sensations is quite remarkable. Works Cited Martini, F.H. and Nath, J.L. (8th edition). (2009). Fundamentals of human anatomy and physiology. San Francisco, CA: Pearson Benjamin Cummings.Myers, D.G. (9th ed.). (2010). Psychology. New York, NY: Worth Publishers.