PRESENTED BY,
V.V.NAGA VARUN
J.SHRAVAN
K.B.GOWTHAM

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INTRODUCTION
 Speech coding is defined as a digital representation of the speech signal .
 Speech compression is achieved by representing each sample of digitized data by lesser number of bits.
 In compression technique the 13 to 16 bits data is represented by an equivalent of 4 or 8 bits.
 In decompression technique the compressed data is converted back to original data.
BLOCK DIAGRAM
HARDWARE
 Efficient hardware is developed by this project to implement the powerful and versatile ADPCM speech compression and decompression algorithm.
 The hardware has been developed using powerful DSP processor ADSP-2105.
 The speech processing system consists of ADSP-2105,CODEC,EPROM,RAM,Amplifier sections,mike and speakers.
FUNCTIONING
 The speech segment to be compressed is fed as input through MICRO PHONE.
 The analog speech signal is digitized by CODEC, compressed by ADSP-2105 and stored in RAM.
 The decompression process can be started by interrupting the processor.
 When the processor is interrupted, the information in memory is fetched by the processor and decompressed and is then fed to CODEC.
 The CODEC converts the digital signal to analog signal. The analog signal is amplified and output through the speaker
FEATURES
The speech compression and decompression technique is used in:
 Cellular Phones.
 Voice Mail Transmission systems.
 Speech recognition systems.