Question: Draw a block schematic for channel encoder and decoder and explain operations

Subject: Speech Processing

Topic: LPC and Parametric Speech Coding

Difficulty: Low

sp(38) • 441 views
modified 8 months ago by gravatar for Manan Bothra Manan Bothra0 written 10 months ago by gravatar for awari.swati831 awari.swati831150

(i) Channel vocoders: Channel vocoder models the vocal tract as bank of band-pass filters. The analysis filter at the transmitter side finds the average square value of energy for input speech 50 times per second.

Channel vocoder transmitter block

Receiver for channel vocoder

(ii) Basically, channel vocoder try to match the frequency profile of the input speech signal.

(iii) They do not reproduce the speech sample.

(iv) It can be seen that not all frequency components speech signal are important. The vocal tract resonant at formants frequency. Formant vocoders are developed to use the frequency.

(v) The range of formant frequency known so the formants are estimated along with bandwidth from a speech segment using a bank of filters designed to match the range of formants.

(vi) At the receiver end, the excitation signal-either a periodic pulse train is used to excite the tunable filter that are tuned to $ R_x $.

written 8 months ago by gravatar for Manan Bothra Manan Bothra0
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