A firework charge is detonated many meters above the ground. At a distance of d1 5 500 m from the explosion, the acoustic pressure reaches a maximum of DPmax 5 10.0 Pa (Fig. P17.33). Assume the speed of sound is constant at 343 m/s throughout the atmosphere over the region considered, the ground absorbs all the sound falling on it, and the air absorbs sound energy as described by the rate 7.00 dB/km. What is the sound level (in decibels) at a distance of d2 5 4.00 3 103 m from the explosion?
Chapter 8: Perception of Sound 8.1 The Human Ear 1. Our ear perceives a wide range of frequencies and amplitudes but also transforms the elastic sound wave into series of electromagnetic pulses, “readable” for our brain. 2. The outer ear consists of the pinna and auditory canal. a. The pinna is the visible, outer part of ear, different in each individual. 3. The inner part of pinna, approximately 2.53 cm across, works like antenna, helping to guide short frequency sound toward the eardrum. a. Important parts of the inner ear are the ossicles – three little bones, shaped like a hammer, an anvil, and a stirrup.