| The discovery of otoacoustic emissions (OAE) is one of the most important progress in hearing physiology and audiology. The analysis of OAE signal is the composition of hearing physiology and audiology . The OAE diagnoses , which is simple, speedy, hurtless, and can be applied to all ages, has great clinic worthiness. But its research and clinic application has been badly restricted by these days' OAE test instrument, either ponderous or costliness. In order to eliminate these disadvantages, We present a new intelligentized OAE test instrument based on correlative research in the world in the last years. Our otoacoustic hearing measurement instrument comprises two parts. One is a stimulus generator and the other is a data acquisition system .The stimulus generator is the core we introduce. It is also the crux of the whole system which attributes to the expanded function and flexibility. In this design we take the lead in applying the technology of DDS to sound stimulus generator , which not only simplifies the hardware, but enhances it's flexibility. Then we elaborate on signal capture. Both stimulus generator and data acquisition system are controlled by synchronal pulse. The stimulus generator and data acquisition system are connected to PC by advanced USB, suiting for development trend. The two parts also can be solely used in auditory evoked potential measurement instrument or middle-ear analyzer. Compact in configuration, mightiness in function , convenience in manipulate and high resolution, high efficiency, low cost are all the characteristics of this instrument.In the end, We give a brief introduce about some common analysis methods on OAE signal. And lay a emphasis on wavelet and improved wigner-vill used in the analysis of SOAE and TEOAE, comparing with the tradition method ,these new time-frequent methods have better time-frequent characteristic, are fitter for the OAE signals. |
