语音的数字化处理、存储及回放资源-CSDN文库

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摘要

传统的磁带语音录放系统因其体积大、使用不便,在电子与信息处理的使用

中受到许多限制。本文提出的体积小巧，功耗低的数字化语音存储与回放系统将

完全可以替代它。数字化语音存储与回放系统的基本原理是对语音的录音与放音

的数字化控制。其中，关键技术在于，为了增加语音存储时间，提高存储器的利

用率，采用了非失真压缩算法对语音信号进行压缩后再存储，而在回放时再进行

解压缩，同时,对输入语音信号进行数字滤波以抑制杂音和干扰,从而确保了语音

回放的可靠质量。

该系统对语音信号分别采用了数据采集直寸直取,欠抽样采样和自相似增量

调制等三种方法,完成了对语音信号32.7s、65.5s、147.4s的存储与回放。前直

AGC将语音信号控制在A/D转换器可控制的范围之内以保证话音信号采样不失真

带通滤波器合理的通带范围有效的滤除了带外噪声，减小了混叠失真。通过后级

补偿电路对输出的语音信号进行了的校正，回放语音清晰。系

统具有自动录音、手动录音、录放音时间显示以及掉电后保护语音信号等功能。

关键词：数字化存储，回放，数字滤波，采样，模/数转换，校正

Abstract

T r a d i t i o n a l t a p e r e c o r d s y s t e m b e c a u s e o f h e a v y u s i n g i n c o n v e n i e n t v o l u m e

t h e i r , r e c e i v e a l o t o f r e s t r i c t i o n s i n t h e u s e o f t h e e l e c t r o n a n d i n f o r m a t i o n

p r o c e s s i n g . T h e v o l u m e t h a t t h i s t e x t p u t s f o r w a r d i s s m a l l a n d

exquisite， the digitized pronunciation of the low power dissipation can substitute it

w i t h t h e p l a y b a c k s y s t e m t o s t o r e . D i g i t i z e d p r o n u n c i a t i o n s t o r e s y s t e m a t i c b a s i c

principle recording and to put sound in pronunciation digital control with playback.

Among them, key t echnology lies in : For increase pronunciation store time , raise

utilization ratio of memory , adopt non- distorted to compress algorithm go on after

c o m p r e s s i n g s t o r i n g t o p r o n u n c i a t i o n s i g n a l , d e c o m p r e s s i n t h e p l a y b a c k ;

Meanwhile, to input pronunciation signal carry on figure strain wave by suppressing

n o is i ng a n d i n t e r f e r i n g , t h u s g u a r a n t e e d t h e r e li a b l e q u a l i t y o f t h e p l a y b a c k o f t h e

pronunciation.

In trod ucing the direct sto re & a c cess of d a ta collection， a nd AGC o n aco ustic

s i g n a l r e s p e c t i v e l y ， t h i s s y s t e m i m p l e m e n t s t h e s t o r a g e a n p l a y b a c k o f a c o u s t i c

s i g n a l w h i c h l a s t s f o r 3 2 . 7 se co n d s , 6 5 . 5 s e n d s o r 1 4 7 . 4 s e c o n d s ; T o i n s u r e t h e

undistorted sampling of speech signal, the pre-AGC limits the speech signal within

the range that can be processed by A/D converter; the reasonable handwidth of hang-

pass filter removes the out-hand noise efficiently and decrease the overlap distortion;

W i t h t h e e m e n d a t i o n b y l a t t e r c o m p e n s a b l e

circuit ， the playback voice is very clear; Beside all above ， this system also realize

the following funcitions: automatic recording manually recording manually recording

,record , record/play time display and the saving of speech signal when power-off .

Keywords: Digital store，Playback Digital Filter，Sample， A/D Convert，Correct

目    录
摘要....................................................................................................I
Abstract............................................................................................II
绪言................................................................................................1
1课题背景...........................................................................................................................1
2课题研究的目的和意义....................................................................................................1
3国内外概况.......................................................................................................................1
2方案比较与论证.................................................................................2
1方案一...............................................................................................................................2
1.1语音编码方案：.....................................................................................................2
1.2 A/D、D/A及存储芯片的选择..............................................................................3
2方案二...............................................................................................................................3
2.1控制方式................................................................................................................3
2.2放大器及A/D、D/A芯片的选择...........................................................................4
3方案三...............................................................................................................................4
3系统总体结构....................................................................................5
电路设计..........................................................................................6
1拾音器...............................................................................................................................6
2放大器的设计...................................................................................................................6
3有源带通滤波器设计........................................................................................................8
4可调稳压电源的设计......................................................................................................10
5 MCS—51系列单片机....................................................................................................10
6 D/A、A/D转换器...........................................................................................................20
6.1 D/A转换器DAC0832的介绍..............................................................................20
6.2 A/D转换器AD574介绍.......................................................................................21
6.3 单片机AT89C51和AD574 的接口原理..............................................................22
6.4 存储器的选取......................................................................................................24
软件设计........................................................................................26
总结与展望....................................................................................28
 致 谢...............................................................................................29
参考文献...........................................................................................30
附录.................................................................................................32
III