The Measurement And Study Of The Binaural Bone Conduction Transfer Function Database

Bone conduction(BC)refers to the way that sound waves are transmitted to the cochlea through the skull to produce auditory perception.According to the characteristics that BC sound can also be transmitted to the inner ear without passing through the outer and middle ears,BC technology can be applied to medical hearing aids,military equipment and daily communication.At present,the research on BC transmission characteristics is mainly through the objective measurement experiment of dry skull or cadaver head,finite element analysis,air-bone conduction cancellation and other subjective experimental methods,but the BC transmission characteristics obtained by these methods are different from the personalizedBC transmission characteristics of real person's head.Bone conduction transfer function(BCTF)reflects the transmission characteristics between the bone transducer and bilateral cochlea,which is of great significance in the application of bilateral BC sound reproduction.Because it is difficult to accurately measure the BCTF which is used to characterize the BC characteristics,there are few studies on the objective measurement of the transmission characteristics between the bone transducer and bilateral cochlea.Based on the otoacoustic emission mechanism of cochlea,this paper will explore the headBC transmission characteristics,and establish a multi-sample BCTF database based on this method.Finally,according to the personalized data in the database,we will study the crosstalk cancellation system of bilateral BC.In order to solve the above problems,in the second chapter,we first study the BC effect of real person's head by evoking swept-tone frequency otoacoustic emissions(SFOAE),and define the relative relationship between the measured otoacoustic emissions and the bone transducer stimulus signal as otoacoustic related bone conduction response function(OAR-BCRF),which is used as the objective characterization of BCTF.Secondly,in the third chapter,according to the measurement method in the second chapter,we measured and analyzed the bilateral BCTF of 31 subjects in different stimulation positions,and explored the validity and reliability of the measurement method through comparative experiments,and the transcranial attenuation data of multiple individuals were analyzed,and found that there was crosstalk in the BC pathway.Since BCTF is closely related to the physiological parameters such as head structure and size,17 physiological parameters of the head were measured and analyzed.Finally,in the fourth chapter,according to the personalizedBCTF in the database,the bilateral BC crosstalk cancellation system was designed,and the crosstalk cancellation filter was designed based on the fast deconvolution algorithm in frequency domain.The best crosstalk cancellation effect was obtained by adjusting the relevant filter parameters,and the subjective and objective evaluation indexes were used to measure the crosstalk cancellation effect.The objective simulation results show that the crosstalk cancellation system has a good channel separation effect at 1?3 kHz,and the channel separation is basically below-50 dB when the gain factor??10^-4 The subjective localization results show that the accuracy of BC localization is improved to a certain extent by using crosstalk cancellation.When using narrow band(2?4.5 kHz)Gaussian noise as test signal,the localization accuracy is better than that of broadband(0.4?10 kHz)Gaussian noise.In this paper,based on the method of obtaining BCTF by evoking swept-tone SFOAE,a fast and accurate BCTF measurement in a certain frequency band is realized.This method provides an objective and effective means to explore the BC transmission characteristics of real person's head,and provides a data basis for the analysis of the commonness and difference of subjects'data and the cancellation of BC sound crosstalk,which helps to better improve the effect of BC sound reproduction.