Lecture 5 - Frequency Domain of Speech

Question 1

When should you use a narrowband or wideband window?

Answer 1

Narrowband (long window) -> if window covers several pitch periods
Wideband (short window) -> if window covers only about one pitch period

Question 2

What’s the difference between using a long and short window

Answer 2

1. Long window -> better frequency resolution
2. Short window -> better time resolution

Question 3

Describe the source-filter theory

Answer 3

1. Source (from the body) -> fundamental frequency and harmonics
2. Filter -> vocal tract shape results in specific resonances (which shapes the formants)

Question 4

Indicate what’s important between formants and pitch.

Answer 4

Formants -> what was said (shorter window)
Pitch -> who was saying (longer window)

Question 5

Voiced vowels are ___

Answer 5

periodic