The document presents an overview of speech recognition, describing it as the conversion of acoustic signals into text and discussing its workings and methodologies. It outlines the advantages, disadvantages, and future potential of speech recognition technology, including its applications in various fields and ongoing research efforts by DARPA. Key points include the distinction between speaker-dependent and speaker-independent systems, the recognition process, and the evolution towards speech understanding and artificial intelligence.

1. SPEECH RECOGNITION
Presented by:
Rakesh C N
IIIrd
Sem MCA

2. Contents
Introduction
Meaning of Speech Recognition
Working of Speech Recognition
Speech Recognition Flowchart
Recognition process Flow Summary
Advantages
Disadvantages
The Future of Speech Recognition
Conclusion

3. Introduction
The process of converting an acoustic signal, captured by
a microphone or a telephone, to set of words.
They can also serve as the input to further linguistic
processing in order to achieve speech understanding.

4. What is Speech Recognition
 It means talking to a computer, having it recognize
whatever we're saying.
 The interdisciplinary subfield of computational
linguistics that develops methodologies and
technologies.
 It enables the recognition and translation of spoken
language into text by computers.

5. It converts PCM (pulse code modulation) digital audio from a
sound card into recognized speech.
It basically uses algorithms through language modeling.
It involves relationship between linguistic units of speech and
audio signals,
 Language modeling matches sounds with word sequences
to help differentiate between words that sound similar.
How Does it Works?

6. Types Of Speech Recognition
1)Speaker-Dependent
2)Speaker-Independent

7. This works by learning the unique characteristics of a
single person's voice.
 New users must first "train" the software by speaking to it.
the computer can analyze how the person talks.
Users have to read a few pages of text to the computer
before they can use the speech recognition software.
1) Speaker-Dependent:-

8. 2) Speaker-Independent:-
It is the only real option for applications such as interactive
voice response systems .
It is generally less accurate than speaker-dependent software.
Speech recognition engines that are speaker independent
generally deal with this fact by limiting the grammars they
use.

10. Step 1:User Input
The system catches user's voice in the form of analog
acoustic signal.
 Step 2 Digitization
Digitize the analog acoustic signal.
 Step 3:Phonetic Breakdown
Breaking signals into phonemes
Recognition Process Flow
Summary

11. Step 4:Statistical Modeling
Mapping phonemes to their phonetic representation using
statistics model.
Step 5:Matching
According to grammar phonetic representation and Dictionary,
the system returns an n-best list
Grammar- the union words or phrases to constraint the range of
input or output in the voice application.
Recognition Process Flow
Summary

12. People with disabilities.
Lower operational Costs.
Advances in technology will allow to implement speech
recognition systems at a relatively low cost.
Users can trade stocks through a voice-activated trading
system.
Speech recognition technology can also replace touch-
tone.
ADVANTAGES

13. Difficult to build a perfect system.
Conversations
•Every human being has differences such as their voice,
mouth, and speaking style.
Filtering background noise is a task that can even be difficult
for humans to accomplish.
DISADVANTAGES

14. The Future Of Speech Recognition
DARPA has three teams of researchers working on Global
Autonomous Language Exploitation (GALE).
A program that will take in streams of information from
foreign news broadcasts and newspapers and translate them.
 "DARPA is also funding an R&D effort called TRANSTAC.

15. Conclusion
At some point in the future, speech recognition may become
speech understanding.
The statistical models that allow computers to decide what a
person just said may someday allow them to grasp the meaning
behind the words.
Although it is a huge leap in terms of computational power and
software sophistication.
Some researchers argue that speech recognition development
offers the most direct line from the computers of today to true
artificial intelligence.