1、 本 科 毕 业 设 计本 科 毕 业 设 计 （2012 届）届） 题目题目 语音录放系统的设计 学院学院 专业专业 班级班级 学号学号 学生姓名学生姓名 指导教师指导教师 完成日期完成日期 2012 年 5 月 摘 要 本论文主要实现语音录放系统的设计。语音录放系统主要包括单片机控制模 块、语音采集模块、语音处理模块、信号放大模块，其中单片机控制模块是整个 系统设计的关键。在语音的录放过程中，单片机通过 SPI 通信方式与语音模块进 行通讯，来实现语音的录音与播放。由于每段录音都对应着不同的地址，因此在 播放录音时，需要发送需要播放的地址即可播放。 语音录放系统的信号处理过程主要包括语音的
2、采集、信号的放大和语音的滤 波。语音经过驻极体传感器，即麦克风，把声波信号转换成电信号。传感器采集 的电信号进过放大电路，放大一定倍数，经滤波、耦合之后送至语音模块。语音 模块对连续变化的语音信号进行采样，抽取其中的语音信号电平，直接存储在语 音芯片 ISD4004 中，因此使得语音自然真实。当语音播放时，需要在语音芯片的 输出段加一个带通滤波器，以滤除音频带宽以外的信号，从而减少杂音的干扰。 STC89C52 单片机的程序，使用 keil 编译程序进行设计和调试完成，其主要功能是 控制语音模块，以及液晶显示模块。 关键词：微控制器；录音放音；ISD4004； ABSTRACT The mai
3、n aim of this paper is to realize the function of voice recording and playback system. The key to the overall system design of the voice recording system which includes a single-chip control module, voice acquisition module, voice processing module, signal amplification module, is MCU control module
4、. In the voice playback process, the microcontroller communicates through SPI communication voice module, thus realizing voice recording and playback. Each recording corresponds to a different address, so the microcontroller just need to send the address of the recording to be played for play back.
5、The signal processing of the voice recording system includes speech acquisition, signal amplification and voice filter. Acoustic signal is converted into electrical signals through electrets sensor, which is also called microphone. The sensor signals will be amplified after flow through the amplifyi
6、ng circuit. Finally it will be send to voice module after filtering, coupling. Continuous acoustic signal is sampled by the voice module, which takes one of the voice signal level, directly stores it in the voice chip ISD4004, and makes speech natural and true. When the recording is played we need a band-pass filter in the voice chip output section, to filter out the signal outside the audio bandwidth thereby reducing noise. The codes of the Microcontroller STC89C52 is designed and test
