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Question 1

What are the three steps in the calculation of cepstral coefficients?

Answer 1

• FT
• In
• IFT

The last transform takes the function back into the cepstral domain.

Question 2

The output c§(т) is the complex cepstrum of signal s. What is the equation that represents this?

Answer 2

Cš(T) = C(T) + C*(т)

This equation shows the relationship between the complex cepstra of the signals involved.

Question 3

What is the formula for the real cepstrum derived from the log magnitude of the spectrum?

Answer 3

cs(T) = F-1 {In|S(w)|}

The real cepstrum is a real and even function of the lag, or quefrency.

Question 4

True or false: The real cepstrum retains phase information from the original signal.

Answer 4

FALSE

Phase information from the original signal has been lost in the process of calculating the real cepstrum.

Question 5

What can replace the IFT in the calculation of the real cepstrum?

Answer 5

Discrete cosine transform (DCT)

This replacement is possible because the real cepstrum is a real and even function of the lag.

Question 6

The cepstral analysis is applied in various fields. Name one example.

Answer 6

• Seismic analysis

Cepstral analysis is also used in speech data analysis.