Acoustics of Vowels and Consonants

What is the source of sound when speaking?

Vocal fold vibration

What is the area of the pharyngeal and oral cavity in production of the /i/ sound?

Large area in pharyngeal cavity and small area in the oral cavity. Lower sounds are amplified in pharynx and higher sounds are amplified in the oral cavity.

What is the area of the pharyngeal and oral cavity in production of the /u/ sound?

Small area in the pharyngeal cavity and large area in the oral cavity. Due to this, the formants will be closer together (F2 will still be higher though)

Describe the difference in ranges of the foramens when producing a high front vowel vs a high back vowel

High front vowel will result in the formants being further apart due to oral cavity resonating higher frequencies

High back vowel will result in formants being closer together since the oral cavity will amplify lower sounds

What are formants?

Frequencies that are amplified in the vocal tract

Describe what F0, F1, F2 mean

F0 - fundamental frequency; the frequency at the vocal fold level

F1 - frequency in the pharyngeal cavity

F2 - frequency in the oral cavity (increase with increased tongue advancement)

What happens to the formants as lip rounding increases?

All formants decrease (major effect on F2)

What is the F1/F2 ratio used for?

Helps us determine what vowel is being produced despite the speakers age or sex

What muscle is used to raise the back of the tongue?

Styloglossus

What does the Vg signal measure?

Defines when the glottal space gets smaller and bigger

When we are producing a sustained vowel sound, how do the vocal folds vibrate

In a near complex periodic way

What does a high pitch F0 vs low pitch F0 represent

High pitch = shorter thinner VFs

Low pitch = longer thicker VFs

How do vocal folds vibrate?

Vibrate as a whole unit but also produce a series of harmonics

What does the output spectrum represent?

Areas of constriction in the vocal tract made by tongue and hard/soft palate

Are vowels produced with open or closed oral cavity?

Open

Are vowels voiced or voiceless

Voiced

How do you calculate F1/F2 ratio

F2 - F1

What is the primary change in the vocal tract that allows us to produce so many different vowel sounds?

Tongue movement/placement

What is different about the production of vowels vs consonants

There is a significant constriction required in the oral/pharyngeal cavity in order to produce consonant sounds

How would you describe a stop?

Release of built up pressure

How would you describe a fricative?

Air being forced through a narrow channel. Sustained noise (like white noise)

How would you describe a nasal?

The velum being lowered so that air can pass freely through the nasal cavity

How would you describe an affricate?

Mix of a stop and a fricative

What sounds characterize a glide?

/w/; /j/ as in yellow

Retroflexed vs bunched tongue?

Bunched = tongue back + up

Retroflexive = not that

What happens during the production of a nasal sound?

The velum lowers opening the velopharyngeal port

What is antiresonance

Happens during production of nasal sounds. Air flows up through the pharyngeal cavity and then into the oral cavity before it is stopped by the closure of lips. When it runs into the lips it goes back where it came from, gets attenuated in surrounding tissue and then goes up through the open velopharyngeal port where the air exits the nostrils.

Do nasal or oral sounds have a higher intensisty

Oral sounds

How is it determined which frequencies are attenuated during production of a nasal sound?

Depends on the position of the tongue

How does antiresonance look on a spectrogram?

Since antiresonance results in a loss of energy, the frequencies that are attenuated will appear white on the spectrogram

How can you determine between a voiced and voiceless sound on a spectrogram

Voiced sounds have a band at the start whereas voiceless sounds do not

What muscle is required to close the velar port?

Palatal levator and uvulus

What muscles are needed to produce a bilabial stop

Orbicularis oris and levator labii superiorius

What muscles are needed to produce an alveolar stop

Superior longitudinal

What muscles are needed to produce a velar stop

Styloglossus and palatoglossus

What are the three main acoustic characteristics of stop sounds

Silent interval, burst, frication interval

What is this called?

Voice onset time

Why do voiced stops have a much lower voice onset time than voiceless stops?

The vocal folds are already adducted so transition into the production of the sound is much faster for voiced sounds

Does more frication represent production of a voiced or voiceless sound

Voiceless

How do affricates look acoustically

They are a combination of both fricatives and stops. Thus they include a silent period, release burst, and frication period (this period will be much longer)

What are the two semivowels

Liquids and glides

What are the acoustics of a glide?

Similar to that of the vowel that follows it. Sound takes the shape of the vowel

What differs about /L/ and /r/ on the spectrograph compared to other sounds

There is a dip in formants (dip in F2)

What is a dipthong?

A sound formed by the combination of two sounds (formants may alter to going upwards or downwards depending on movement of the tongue)

What is coarticulation?

Production of speech in context. Individual segments influence each other and modify the acoustic characteristics of adjacent sounds

What is anticipatory coarticulation

Upcoming sound influencing the production of a preceding sound

What is carryover articulation?

Preceding sounds can change the production of sounds that follow

What is coarticulation due to?

Place and manner of neighboring sounds

What does coarticulation effect?

Placement/manner, voicing, nasalization and duration

What do we mean by duration?

Sounds are longer in duration when isolated rather then when in a string of sounds

Why does the length of a speech signal depend on voicing characterstics

Words ending in voiceless sounds are quicker since the VFs turn off faster. Words ending in voiced sounds are produced for longer because the vocal folds don’t need to turn off

How is nasalization affected by coarticulation?

Vowels before/after a nasal sound have antiresonance properties because we are preparing by opening the velopharyngeal port so there is some flow through the nasal cavity

What is the purpose of intonation

To carry info with a string of words to create a different meaning through pitch changes

What is the purpose of stress in connected speech

Changes the meaning we are trying to convey

How does stressed syllables look on a spectrograph

Frequency is higher, intensity is higher, and duration is longer

What does /j/ sound like?

/i/, high front

What does /w/ sound like?

/u/, high back