Speech Recognition System Using Ic Hm2007
Speech Recognition System Using Ic Hm2007
Speech Recognition System Using Ic Hm2007
INDEX
Objectives
Introduction Difference between speech and voice recognition The logic Study of components used Methodology Challenges faced and their solution Advantages and disadvantages
OBJECTIVES
To develop a speech recognition system capable of
INTRODUCTION
Speech is a natural mode of communication for people by which they
express their views and messages as voice utterances. The electronic approach of speech recognition is to convert the speech into an electronic signal. Analog representation of speech.
Voice recognition
It is a speaker dependent
system. The main function of this system is to recognize the word spoken by the speaker. It concerns with what is being spoken and not who the speaker is.
system The main function of this system is to recognize the speaker first and then the words It concerns with who is speaking and what is being spoken.
THE LOGIC
IC HM2007
Single chip voice recognition CMOS.
Speaker dependent. External RAM support. Maximum 40 word recognition (.96
second). Maximum word length 1.92 seconds (20 word). Microphone support. Manual and CPU modes available. Response time less than 300 milliseconds. 5V power supply.
55 = word to long 66 = word to short 77 = no match Pressing 99 and then clear clears all the data inside the RAM.
8k x 8 SRAM
TTL-compatible inputs
and outputs. 13 address pins 8 I/O pins. Automatic power-down when deselected. Static RAM organized as 8192 words by 8 bits.
IC 74lS373
Consists of eight latches
with 3-state outputs for bus organized system applications. D1-D8 are data inputs. Q1-Q8 are output pins. Used for controlling two 7 segment drivers.
control signals for 7 segment display. ABCD are the BCD inputs. a-f are outputs for the 7 segment display.
7 SEGMENT DISPLAY
a-g are the connected to
output of IC 7448. Can display all hexadecimal digits from 0-9 and A-F.
METHODOLOGY
Trained words and codes fed in RAM
Data from RAM to latch
circuit. The IC provides an analog front end, voice analysis, speech recognition and system control. The IC gets the analog signal from mic and converts it into digital codes. These codes are given specific notations or codes by the user and are stored in the RAM this is called as training. Now whenever the IC gets the same speech input it will give the same notation as given before.
it has been reduced by using a band pass filter of range 300Hz - 3.1kHz .
Homonyms
Homonyms are words that sound alike. For instance the words cat, bat, sat and fat sound alike. Because of their like sounding nature they can confuse the speech recognition circuit.
the voice recognition technology for their works. As the speech recognition technology needs only voice and irrespective of the language in which it is delivered it is recorded, due to this perspective this is helpful to be used in any language.
DRAWBACKS:
If the system has to work under noisy environments, background noise may
corrupt the original data and leads to SS misinterpretation. If words that are pronounced similar for example, their, there, this technology face difficulty in distinguishing them.
FUTURE SCOPE
No typing by keyboard would be
required as your voice will act as an interface between you and your computer
various
using speech for controlling devices like car stereos, GPS ,home appliances and various other devices.
Sub vocal speech recognitionThe normal speech recognition can be extended to sub vocal speech recognition. This technology enables speech recognition through the vocal utterances. It is a boon to all the dumb people or people who face problems in speaking.