Design and Implementation of Speech Based Scientific Calculator ABSTRACT IN RECENT DAYS SPEECH RECOGNITION BASED SYSTEMS ARE GAINING MORE PROMINENCE AND ARE USED IN A WIDE RANGE OF APPLICATIONS. CALCULATOR HAS BECOME AN INDISPENSABLE PART OF OUR LIVES, USED AT HOME, AT LOCAL RETAIL SHOPS OR AT WORKPLACES LIKE BANKS, IT COMPANIES, MEDICAL LABORATORIES ETC. SPEECH RECOGNIZED CALCULATOR IS ONE OF THE SPEECH RECOGNITION SYSTEMS

Introduction• Speech is the vocalized form of human communication. It

ranges from 90 Hz to 7,000 Hz. Each spoken word is created out of the phonetic combination of a limited set of vowel and consonant speech sound units. • Speech recognition is the process of automatic extracting

and determining linguistic information conveyed by a speech wave using computers. This Speech recognized calculator can be implemented by using linear predictive coding (LPC) method. • Implementation of this system includes two stages namely a) Training phase b) Testing phase

What is Linear Predictive Coding(LPC)..?

• Its one of the most important speech analysis techniques.• The basis of LPC model is that, for a given speech sample at

time n, s(n), can be approximated as a linear combination of the past p speech samples, such that

s˜(n) ≈ a1s(n − 1)+ a2s(n − 2)+ aps(n − p) • where the coefficients a1, a2,.... ap are assumed to be

constant over the speech analysis frame in the equation represents the order of the linear predictor.• LPC can be implemented using either Auto Correlation

Method, Covariance Method or Lattice Method  

Block of MATLAB based SRC

• 1. Speech Acquisition • 2. Speech Extraction • 3. Speech Recognition • 4. Pattern Training and Decision Logic

SPEECH ACQUISITION

• Speech acquisition refers to the process of acquiring the required speech input from the user. • During speech acquisition, speech samples are obtained

from the speaker in real time and stored in memory for preprocessing. • As the articulation bandwidth of voice is 300 Hz to 3 kHz.

According to the Nyquist Sampling Theorem ,the sampling frequency is 8kHz as the minimum sampling rate. • In our project we have chosen the sampling rate to be 10

kHz so that more samples can be obtained which will be a greater advantage in further processing.

SPEECH EXTRACTION• Now recorded speech interval is fed to the extraction stage

where the uttered digit or the operator is extracted from the entire recording interval.• The recording interval consists of voiced segments and

unvoiced segments.• Below fig shows the extracted information due to sampling

of recorded information in this stage

Title and Content Layout with Chart

Two Content Layout with Table• First bullet point here• Second bullet point here• Third bullet point here

Group 1 Group 2

Class 1 82 95

Class 2 76 88

Class 3 84 90

Title and Content Layout with SmartArt