Subject: Speech Processing

Topic: Speech Analysis in Time Domain

Difficulty: Medium

Why do we consider short time representation of speech signals? What do you mean by windowing? Explain the concept of short time speech processing with suitable general block diagram.

(i) Analyzing speech in the time domain has the advantage of simplicity in calculation and physical interpretation.

(ii) Several speech feature relevant for coding and recognition occur in temporal analysis e.g. energy (or amplitude), voicing and fo.

(iii) Energy can be used segment speech in automatic recognition systems, and must be replicated in synthesizing speech accurate voicing and fo. estimation are crucial for many speech coder.

(iv) Other time features e.g. zero-crossing rate and auto-correction, provide inexpensive spectral details without formal spectral technique.

(v) Windows are mostly used with FIR filters that have limited impulses to work with. This allow Discrete Fourier Transform (DFT) of the windowed speech and also the phase is not allowed.

Short-time speech processing:

General short-time processing