CSD200 Speech Acoustics and Sounds

Theory of Speech Acoustics

The output of the vocal tract is the product of a source and filter.

Source

Vibration of the vocal folds, which generates a

fundamental frequency and a series of harmonics

(like doorbell buzzer)

Filter

The vocal tract, which can be thought of resonating like a

tube or pipe with various constrictions

What changes the resonant frequencies?

The LOCATION and EXTENT of the constrictions of the vocal tract

How are different sounds distinguished?

Their different vocal tract configurations (“tube-shapes”), generate

different resonant frequencies.

Phoneme

Smallest meaningful speech sound unit

Vowels

Open vocal tract

Consonants

Constricted vocal tract

Determining factors of speech sounds

– Place of articulation

– Manner of articulation

– Voicing (voiced or voiceless)

Voiced

Speech sound requires vibration of vocal folds

Voiceless

Speech sounds does not require vibration of vocal folds

Manners of articulation

Stops

Fricatives

Nasals

Liquids

Glides

Places of articulation

Bilabial

Labiodental

Linguadental/Interdental

Alveolar

Palatal

Velar