LINGUISTICS Sound Structure Part 1: Speech Sounds

LING001 Sound Structure LINGUISTICS Sound Structure Part 1 Speech Sounds 2009 Sound Structure of Language Many different topics in phonetics and phonology Anatomyphysiology etc of the vocal tract The cognitive status of speech and phonology, and how it interacts with other subsystems of language The application in reading speech technology and therapy The Vocal Tract The human head seen in a sagittal view; as if it had been cut down the center This system has both survival and speech functions.

Sound Structure

Part 1: Speech Sounds

2009

Sound Structure of Language

• Many different topics in phonetics and phonology

• Anatomy/physiology etc of the vocal tract

• The cognitive status of speech and phonology, and

how it interacts with other subsystems of language

• The application in reading speech technology and

therapy

The Vocal Tract

• The human head seen

in a sagittal view; as if

it had been cut down the center

• This system has both

survival and speech functions

Evolutionary History

• The human vocal tract shows a lowering of the

larynx with respect to its position in other primates

• This has consequences for speech, and also the

consequence that humans choke more easily than other primates do

• While it has been suggested that this is an

evolutionary adaptation that highlights the

importance of speech the case of the

Neanderthals it seems to be the case that other species have this anatomical feature as well

Lowered Larynx: Uniquely

human?

QuickTime™ and a Cinepak decompressor are needed to see this picture.

Sounds of Language

• In principle like a saxophone

• consonants have some air constrictions, vowels

don’t: neurolinguistic deficits show differential

difficulties (Caramazza et al 2000)

• Speech synthesis systems are modeled after the

vocal tract

• 1950’s Rip, mix, and burn: find the acoustic sound

for /k/, /æ/, and /t/, and glue them together

• Speech doesn’t have pauses between words or

consonants and vowels!

When Consonant Meets Vowel

• Front vowel: /i/ (bee), Back vowel: /u/ (boo)

• When consonants meet vowels: say “bee” but

don’t say it!

• Co-articulation

When Consonants Meet Vowels

• same burst of air (dark vertical line)

• different vowels to follow /i/, /a/, /u/ (bee, bot, boo)

• speakers perceive different consonants (pi, ka,

pu)

• no reliable acoustic cues for perception

Bell says

• Alexander Graham Bell, the inventor of telephone

• “What we term an “element of speech” may in

reality be a combination of positions The true

elements of articulation, I think, is a constriction or position of the vocal organs rather than a sound

Combinations of positions yields new sounds, just

as combinations of chemical elements yield new

substances Water is a substance of very different character from either the gases of which it is

formed; and the vowel oo is a sound of very

different character from that of any of its

elementary positions.” (1900)

Bells’ alphabet

Notation for speech sounds

• Linguists use a standardized system of notation

called the International Phonetic Alphabet (IPA) to represent speech sounds in a consistent fashion

• This uniform system can be used to represent

sounds from any of the world’s languages

Articulators in the Vocal Tract

Vocal

The Vocal Cords

• The vocal cords are a pair of muscular flaps that

can be brought together to form a seal, or opened

to permit airflow:

QuickTim e™ and a Video decom pressor are needed to see this picture.

Vocal Cords, Cont

When the vocal cords are vibrating to create a

sounds with a pitch, a voiced speech sound

If you hold your hand to your throat, you can

feel vibration for the voiced sounds, as well as

for nasals like [m], [n], and vowels like [a]

Place of Articulation

• Where the sound is made (not an exhaustive list

for English)

• (bi-)labial: with the lips ( b, p )

• alveolar: behind the teeth ( t, d )

• velar: back of the tongue raised to soft palate

(velum) ( k, g )

labial alveolar velar

Manner of Articulation

• How the sounds are produced

• Stop: complete closure, with airflow stoppage (b, p )

• Fricative: narrow opening with forced air (s, z, f, v )

• Nasal: air allowed to pass through nose (m, n,

ŋ=ng )

Mini Summary

alveolar velar

labial

ŋ

In recitation

• You will learn a finer grained dissection of speech

sounds in languages (in particular English)

• You will learn to transcribe speech in terms of IPA

symbols (a chart is included in the reading packet)

• A system like that used above is used for vowels as

well:

• High/mid/low: height of tongue in mouth

• Front/central/back: frontness or backness of tongue

in mouth

• Rounded/unrounded: state of the lips during

production of the vowel

• Tense/lax: degree of tenseness in the tongue

English Vowel Chart

IPA Vowel Chart

Notes on the chart

• Many Americans don’t distinguish between caught

and cot: an example of language change

• English also have diphthongs: complex vowels that

combine a vowel with another vowel/semi-vowel

• /aɪ/ (eye)

• /aʊ/ (cow)

• /ɔɪ/ (boy)

Articulatory Sources Online

• If you're interested in the physical aspects of sounds,

the following is a great website with clear explanations

and animation:

• If you're interested in hearing sounds from many

languages other than English with their appropriate IPA

Cognitive Role of Phonetics

• Perception

• Toward phonology

Pa vs Ba

• b: voiced (/ba/), p: voiceless (/pa/)

• ba: vocal cord vibrates right away, pa has 80 ms

delay

• What happens in between?

Seeing Speech

QuickTime™ and a

Sorenson Video 3 decompressor

are needed to see this picture.

Speech Perception

• Speech is perceived as discrete categories

• speech is represented atomically

• Discrete units out of continuous stimulus, fast,

invariance out of variations, which is by no means the mode of all perceptual systems (height, weight, loudness, brightness, angle, etc.)

• Argued to be a unique feature of human language

system and evolution

• food for thought: is categorical perception unique to

speech?