A Study Of Chinese Language Intelligibility Based On Bone Conduction

Bone conduction is a way of transmission,which has many advantages such as strong anti-interference ability and the ability to monitor external acoustic environment information.Bone conduction transducers have been used in many occasions.However,the coupling position of the head,the vibration mode of the skull,and its own frequency response will affect the speech intelligibility of bone conduction.Especially in occasions with high real-time communication requirements such as emergency rescue,speech intelligibility will directly affect the quality evaluation of the communication system.Foreign scholars mostly conduct bone conduction speech intelligibility studies based on Western languages,or explore the background for military applications.The study of bone conduction Chinese speech intelligibility has not been reported yet.Bone conduction speech intelligibility has different influencing factors from air conduction,such as location,Occlusion,etc.This requires further study.The bone conduction vibrator is the core component of the bone conduction transducer.The wearing position of the bone conduction vibrator will affect the effective level and spectral content of the acoustic signal,so the choice of the wearing position of the bone conduction vibrator is the basis for the study of bone conduction Chinese speech intelligibility.This article will conduct research from the choice of the wearing position of the bone conduction vibrator and exploring the factors affecting the bone conduction Chinese speech intelligibility.The specific work and innovation are reflected in the following three aspects:(1)Studying the wearing position of the bone conduction vibrator.The bone conduction hearing threshold measurement and the subjective evaluation experiment of sound quality were carried out in 6 positions of the head.The hearing threshold can compare the ability of different wearing positions to receive pure tone signals.The hearing threshold of the condyle is the lowest and the mandible is the highest.The results of subjective evaluation of sound quality show that the subjects have the highest subjective preference for the sound quality of the condyle,followed by the mastoid.The position of the condyle performed best in the two experiments,and it is a suitable choice for the wearing position of the bone conduction vibrator.(2)Combined with the characteristics of Chinese pronunciation,The?GB 15508-1995Acoustics-Speech intelligibility test method?is selected to study the bone conduction Chinese speech intelligibility under the influence factors such as signal-to-noise ratio,background noise type,wearing position and occlusion,and analyze the intelligibility gap between air-bone conduction.The experimental results show that the speech intelligibility score of air conduction is higher than that of bone conduction.The signal-to-noise ratio factor affects bone conduction Chinese speech intelligibility,and the intelligibility decreases significantly under the condition of low signal-to-noise ratio.The change of wearing position will affect bone conduction Chinese speech intelligibility score.The occlusion effect can improve the bone conduction Chinese speech intelligibility score.The different types of earphones have different effects in improving bone conduction Chinese language intelligibility scores after ear occluded.The in-ear headphones have the best improvement effect,the effect of full open headphones is the worst..(3)In order to improve the efficiency of acoustic speech intelligibility testing,this paper uses open source frameworks to build a bone conduction Chinese speech intelligibility test system based on ?GB 15508-1995 Acoustics-Speech intelligibility test method?.The purpose is to reduce the problems of long manual judging time,high probability of misjudgment,and long time-consuming statistical analysis of results.