Research Of Audio Signal Spectrum Analyzer Based On Sound Card

With the development of computer technology and signal processing theory of complex change rapidly, the analog signals are vulnerable to interference can be transformed into digital signal processing. A typical example is the application of the voice signal, digital signal processing theory is the audio analysis, and the digital signal is the premise of digital signal processing, audio analysis described in this paper is the digital audio signal as the object of analysis, signal analysis, relevant parameters were obtained through the analysis of time domain and frequency domain.The frequency range of the human can hear about from 20 HZ to 20 KHZ, including our speech room located in the 300 HZ to 3400 HZ or so, the sound through the simulation equipment save and play present analog audio form, the analog signal become digital audio in digital audio technology, with the development of computer, now equipped with a sound card, in frequency acquisition range audio has the performance of no less than professional acquisition card, which provides us a new way to generate audio analyzer with low cost.NI company developed the graphical editing language LabVIEW, and development of virtual instrument played a role in promoting the absolute, the virtual instrument combined with the computer, realize the function of measuring instrument by software can provide digital processing method, application interface and modular rich LabVIEW language, users can clearly operating instrument hardware, real-time to test data analysis and processing.Audio analysis system in this paper mainly includes three parts: the collection and storage, signal analysis, signal processing. The data acquisition program based on user provided audio formats from the sound of speech signal acquisition. The data acquisition process is divided into three steps: initialization / allocation and release the sound card, sound card signal sampling. The user can through the waveform display window directly on the original acquisition signals are observed; the collected signal is sent to the measurement and analysis of signal measurement and analysis processing module.In this paper, using the platform of LabView virtual instrument technology and DSP technology of PC, the design of a high sampling precision, the middle sampling frequency virtual audio signal analysis system based on general computer sound card. If you configure multiple sound cards in parallel on a PC, only slightly modified, can constitute a multi channel audio signal acquisition and analysis system. The system in this method has a high performance price ratio, strong versatility, can be extended to the measurement and laboratory speech recognition, noise monitoring and other engineering applications, has good practicability. The innovation of this paper: the analysis of audio signal acquisition, LabView platform and common computer based on sound card, and the error problem of real audio signals in the measurement gives the corresponding solution. The scheme not only can be used for audio signal analysis of the laboratory environment, can be further extended to the audio signal in industrial detection and intelligent signal analysis system...