iosr-JVSP   Volume-4 ~ Issue-1 ~ Jan-Feb 2014

ABSTRACT: In speech analysis, the voiced-unvoiced decision is usually performed in extracting the information from the speech signals. In this paper, we performed two methods to separate the voiced- unvoiced parts of speech from a speech signal. These are zero crossing rate (ZCR) and energy. In here, we evaluated the results by dividing the speech sample into some segments and used the zero crossing rate and energy calculations to separate the voiced and unvoiced parts of speech. The results suggest that zero crossing rates are low for voiced part and high for unvoiced part where as the energy is high for voiced part and low for unvoiced part. Therefore, these methods are proved more effective in separation of voiced and unvoiced speech.

Key woeds: Devnagari script, zero crossing rate,energy of speech signal.

[1] Bachu R.G., Kopparthi S., Adapa B., Barkana B.D.Separation of Voiced and Unvoiced using Zero crossing rate and Energy of the Speech Signal
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ABSTRACT: In this paper, our main focus is to reduce computation delay proposed in previous FFA algorithm based FIR digital filter. Parallel FIR filter structure with fast finite-impulse response (FIR) along with symmetric coefficients reduces the hardware cost, under the condition that the number of taps is a multiple of 2 or 3. . The proposed parallel FIR structures exploit the inherent nature of symmetric coefficients reducing half the number of multipliers in sub filter section at the expense of additional adders in preprocessing and post processing blocks. Exchanging multipliers with adders is advantageous because adders weigh less than multipliers in terms of silicon area; in addition, the overhead from the additional adders in preprocessing and post processing blocks stay fixed and do not increase along with the length of the FIR filter, whereas the number of reduced multipliers increases along with the length of the FIR filter. The proposed parallel filters uses normal adders (full adder and ripple carry adder) that take more time to execute the program. Therefore, we replaced Ripple Carry Adder (RSA) with Carry Save Adder (CSA) and finally presented the comparison between the timing delays with RSA and CSA. Overall, the proposed parallel FIR structures can lead to significant hardware savings for symmetric convolutions from the existing FFA parallel FIR filter, especially when the length of the filter is large. All the simulations observed in modelsim6.4b simulator, synthesis by Xilinx ISE tool.

Keywords: CSA (carry save adder), FFA, FIR.

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