a. what is the amplitude of the sound wave that represents hearing
Sound is the sensing of a vibration as it propagates trough a medium. Without a medium, there can be no sound. The speed of propagation depends on the elasticity and density of the medium, the medium itself is not required to move, it the terms that it is only required to support the propagation of the vibration. Note: In the case of a repeating sound wave, such as the sine wave of a pure tone, amplitude represents the pressure difference between atmospheric pressure and the maximum pressure of the wave. The speed at. which a compression propagates through the medium is the wave. speed, but this is different than the speed of the molecules themselves. wavelength, Pressure vs. Position. The pressure at a given point in a medium fluctuates slightly as sound. waves pass by. Place theory of hearing. The proposal that the frequency of a sound is indicated by the place along the organ of Corti at which nerve firing is highest. Modern place theory is based on Békésy's traveling wave theory of hearing. The reciprocal of the. period is the frequency. Both Graphs: Sound waves are longitudinal even though these graphs. look like transverse waves. Nothing in a sound wave is actually. waving in the shape of these graphs! The amplitude of either graph. corresponds to the loudness of the sound. The absolute pressure. matters not. For loudness, all that matters is how much the pressure. deviates from its norm, which doesn’t have to be much. In real life. the amplitude would diminish as the sound waves spread out. Just as the amplitude of a sound wave relates to its loudness, the. frequency of the wave relates to its pitch. The higher the pitch, the. higher the frequency. The frequency you hear is just the number of. wavefronts that hit your eardrums in a unit of time. If you're seeing this message, it means we're having trouble loading external resources for Khan Academy. If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked. 1 Other standing waves have multiples of f 0 {\displaystyle f_{0}} 's wavelength. 2  For a tube with one end closed, only the odd multiples of f 0 {\displaystyle f_{0}} support a standing wave, and f 0 {\displaystyle f_{0}} is 4 L {\displaystyle 4L} .  This is a model for the ear canal. Each Hz represents one wave cycle per second. If our ears are working perfectly, we can hear frequencies from about 20 Hz (for example, the largest organ pipe) to 20,000 Hz (for example, some dog whistles). As we move away from the source of a sound, the pressure drops approximately in proportion to the distance. As the distance from the sound source doubles in length, the sound pressure level is reduced by half. The height and depth of sound waves is referred to as amplitude or loudness. As the amplitude increases, the volume increases. Our ears can detect sound over a very wide range of amplitudes, which are often measured and described in terms of decibels (dB). The softest sound humans can hear is approximately 0 dB. Sound depends not only on the point of the initiation of vibration (origin), since the medium may absorb or alter the propagation of the vibratory waves it is dependent also on the location of where the sensing is done and the sensor capabilities of processing those sound waves, as waves may have different frequencies.
Approximately 0 dB.