Experimental And Simulation Study Of Water Drop Sound Steps In Southern Hebei Province

Water drop sound steps are the steps with special acoustic phenomena,which were formed by accident.When the footsteps or clapping sound propagate some distance along the steps,they become sound like water drops.The appearance of this acoustic landscape enriches the interest and cultural connotation of the local scenic spots.It attracts a large number of visitors.The soundscape of water drops greatly enriches the tourist experience from the sense of hearing.Water drop sound steps are very rare.At present,scholars have little research on this peculiar acoustic phenomenon.People do not know enough about its scientific connotation,and folk even associate its strange acoustic phenomena with mythology and legends.The sound field characteristics and influencing factors of water drop sound steps are studied scientifically.This will benefit the acoustics of popular science.It will provide a basis for the scientific protection and the design of the acoustic steps.First,the field investigation and geometric mapping are carried out on the steps of the Emperor Tomb and Tianyuan Mountain.In order to study the sound field of the two steps scientifically,the acoustic experiment is designed and the field test is carried out according to the sound field characteristics.In the experiment,the sound source is arranged in the center of step geometry.In the longitudinal,oblique and transverse direction of the sound source,the equidistance measurement points are arranged to test the changes of the frequency and sound pressure changes in the time domain during the propagation of the sound on the step.In order to further analyze the influence of related factors on the step sound field,this paper establishes the computer model of the step of Emperor Tomb and Tianyuan Mountain based on the acoustic simulation software.The characteristics of the sound field are simulated.The simulation results are compared with the experimental results to verify the accuracy of the computer simulation.Finally,the influence factors of step size,guardrail and slope were simulated by control variable method,and the related factors were analyzed.Finally,according to the field investigation,the acoustic test and the computer simulation results,the protection and design suggestions on the soundscape of water drop sound steps are put forward.The results show that the change of the spectrum of the sound source mainly occurs on the near step surface,when the source sound is propagating along the stepof Emperor Tomb and Tianyuan Mountain.And when the sound source is located in the center of the step,the acoustic phenomenon is most obvious along the sound source.The steps of Emperor Tomb and Tianyuan Mountain screened the spectrum of the sound on the steps,so that the spectrum of the source's voice gradually formed a spectrum dominated by a certain frequency.It makes the ear sound like a drop of water droplets in the bucket.It was found that the dominant frequencies of the steps of Emperor Tomb and Tianyuan Mountain were 500 Hz and 400 Hz respectively.The computer simulation results show that the slope has less influence on the dominant frequency of the spectrum.The maximum D value of the step cross section has an effect on the size of the dominant frequency of the spectrum.The open outdoor sound environment provides the conditions for the formation of water drop sound.The solid barrier can effectively enhance the acoustical effect of the steps.