摘要本文介绍的数字化语音存储与回放系统将完全可以替代传统的磁带语音录放系统。其基本原理是对语音的录音与放音的数字化控制。本文第1章是对课题的一些现状背景的介绍，2,3,4章是对整个系统设计的介绍。数字语音录放系统主要由三部分组成：第一，语音处理，包含编码和压缩；第二，语音录放系统的硬件设计；第三，语音录放系统的软件设计。经测试，本系统具有语音拾取，数字化存储和回放功能。对300Hz-3.4kHz范围内音频信号进行存储和回放，低频段效果较好，高频段稍差。通过提高采样频率，高频段音质可以得到改善。26410
关键词  数字化存储，回放，数字滤波，采样，模/数转换
毕业论文设计说明书外文摘要
Title    Design of Digit-Voice Recorder and Playback System                      
Abstract
This article describes a digital voice storage and playback system can replace traditional tape voice recorders systems. The basic principle is to voice recording and playback of digital control. Chapter 1 of this article is subject status of the background of some description, 2,3,4 chapter is an introduction to the entire system. Digital voice recording system is mainly composed of three parts: first, speech processing, including encoding and compression; second, voice recording system hardware design; third, voice recording system software design. After testing, the system has voice picking, digital storage and playback capabilities. The range of 300Hz-3.4kHz audio signal storage and playback, better low frequency, high frequency somewhat less. By increasing the sampling frequency, high frequency sound quality can be improved.
 Coding part of the use of a simplified ADPCM, in a certain compression ratio and improved the quality of playback time. AGC amplifier unit to automatically adjust with the signal strength, good control of the output is relatively stable. The same filter with a reasonable range of effective filter passband of the band noise, reducing the aliasing distortion. After the adoption of the output level compensation circuit to correct the speech signal.
Keywords  Digital store，Playback， Digitalfilter，Sample， A/D Convert
 目   次
1  绪论    1
1.1 系统方案论证    1
1.2 课题背景    2
1.3 研究成果现状    3
1.4 设计要求和指标    3
1.5 论文研究内容和目的    4
2 语音信号及编码    5
2.1 语音信号    5
2.2 数字音频原理    5
2.3 语音编码    8
2.4 信号的编码    10
3 系统硬件设计    11
3.1 拾音器    12
3.2 放大器的设计    12
3.3 可调稳压电源的设计    14
3.4  D/A、A/D转换器    16
3.5 存储器的选择    18
3.6 键盘的设定    19
4 各模块接口原理    20
4.1 AT89C51和AD574 的接口原理    20
4.2 DAC0832 与单片机的接口原理    21
4.3 存储芯片与单片机的接口原理    22
4.4 系统接口总图    23
5 系统的校正与软件设计    24
5.1校正    24
5.2 软件设计流程    25
6 系统调试与测试    26
6.1 系统调式    26
6.2误差分析与系统测试结果    26
结  论    29
致  谢    30 数字化语音存储与回放系统的设计及电路图:http://www.751com.cn/tongxin/lunwen_20591.html