Epidemiology Of Sound Lab Report

Introduction

For the perception of an organism senses are essential. It is important to interact with the environment and for survival. Several organs are specialized into a given sense, they individually contribute to it, whether it is sight, hearing, touch, smell or taste. Those five senses are the most common ones but several other senses exist, for example for temperature or for pain. In humans, the specialized organs, which have specialized cells, respond to particular stimuli.

Nowadays the ability to hear is decreasing considerably. “360 Millions people worldwide have disabling hearing loss” due to several factors such as hereditary, diseases, excessive noise or ageing. Excessive noise is an interesting factor, especially in our century,

It is useful for distant warnings and communication. This is the detection of vibrations. It is a mechanical wave that travels through different mediums such as air or water but also through solids like in different metals. Sound wave travel through those mediums and they are created by vibration of object, which causes the air to vibrate as well. The vibrating air reaches the ear where the eardrums can start to vibrate and therefore the brain can interpret it as a sound. This process is done by the auditory system. Sound waves are put into graphs and the resulting curve is known as the “waveform” Even though the waveform is represented in two dimension, in real life this is three dimensional and it goes all around from its source. Waveform corresponds to a different air pressure. When the curve is high, the pressure is high in the air. On the other hand when the curve is low, the pressure is low. This is a pattern, which is interpreted as a sound by the

The impedance is the change between two mediums. Vibrations have to defeat this impedance going trough the outer and middle ear, known as the sound conductive mechanism. “Vibration is poorly transmitted at the interface between two media which differ greatly in characteristic impedance (product of density of the medium and speed of sound within it, pc), as for example air and water.” The inner ear works perfectly well but sound connect go through the other parts to be transmitted to the brain. This type of hearing loss concerns all the frequencies, but much more on the lower