There are studies indicate that audible sound wave could have effects on propagation growth through catalyzing hearing sense organs, which would bring a series of physiological and biological chemistry reaction. The sound-pressure level and frequency are important factors in propagation growth. In this study, an experimental system of audio generator was developed for investigating sound wave effect on propagation growth promotion, and an embedded development platform based on ARM+DSP+FPGA was built for the system. The DDFS(Direct Digital Frequency Synthesis) method was used to make various waveforms in the system. A feedback analysis networks was added in the system for reliable output of sound waves. Results show that the audio generator system can produce sound waves with frequency of 20 Hz~20,000Hz accurately and make octave analysis of the sound in experimental environments. The new-type audio generator system will facilitate scientific researches on the field of acoustic biology.