A virtual personal assistant is a software agent that can perform tasks or services for an individual using speech recognition and natural language processing. It extracts features from voice commands using techniques like MFCC and matches them to reference templates to understand commands. Neural networks are used for pattern recognition and machine learning allows the assistant to learn from experience and improve over time. Virtual assistants have many applications and provide an efficient way to interact with mobile devices through speech.

1. Virtual Personal Assistant
Designed by : Siddhesh Ravindra Nanche

2. Introduction
• A v irt ua l a ssist a nt is a so f tw ar e ag en t th at can
p er f o rm task s o r ser v ices f o r an in d iv id ual.
• To activ ate a v ir tu al assistan t u sin g th e v o ice, a w ak e
w o r d mig h t b e u sed .
• Vir tu al assistan ts can p r o v id e a w id e v ar iety o f
ser v ices.
• I t main ly u ses Sp eech r eco g n ition tech n iq u e.

3. Basic Structure
of the System

4. Algorithms Used
• Training Algorithm
• Pattern Recognition Algorithm
• Voice Recognition Algorithms
• Word Selection Algorithm

5. Processing of speech signals

6. Feature Extraction Methods
Perceptual Linear Prediction(PLP)
Relative spectra filtering of log domain coefficient PLP(RASTA-PLP)
Linear Predictive Coding(LPC)
Predictive cepstral coefficient(LPCC)
Mel scale cepstral Analysis(MEL)
Mel frequency cepstral coefficient(MFCC)

7. Method Resources
required
Popularity Implementa
tion
Multi
Speaker
Multi
Language
PLP LOW HIGH EASY NO NO
LPCC HIGH LOW DIFFICULT YES YES
MFCC MODERATE HIGH MODERATE YES YES
Comparison of Feature Extraction Methods

8. Voice Recognition
Algorithms using
M e l
F r e q u e n c y
C e p s t r a l
C o e f f i c i e n t
(MFCC) method
Start
Record Voice Command
Get MFCC vector & Store into
reference template
Get measuring similarity between training & testing
input voice signal
Received voice command
Match with
reference
template
Send the signal to activated command
No
End
yes

9. Neural Network

10. General Diagram of neural network

11. structure of a neural network with a feedback.

12. Equations used in calculation of network
F o r H i d d e n L ay e r
F o r N o n - L i n e a r A c t i v a t i o n F u n c t i o n
F o r E r ro r S y s t e m F u n c t i o n

13. ADVANTAGES
Work processes become more efficient
 learns as it works
improved even further
Who engage in mobile dictation need scarcely change their routine
improves efficiency, leads to more structured work

14. Applications
• Google Now
• Google Assistant
• Apple’s Siri
• S Voice
• Microsoft’s Cortana
• Mycroft AI

15. Conclusion
 Virtual Personal Assistant has very importance now-a-days. Use of this leads to
smart work.
 It gives efficient way to communicate with hand-held device.
 There are many ways to use or implement this system.
 This system learns as it works, and improves efficiency.

16. Thank You