Language and Perception - Brown University

Language and Perception

Preliminary Considerations

Terminology

• Needed: shared means of identifying and
describing speech sounds

• Some writing systems are sound-based,
but common alphabet is insufficient

• G.B. Shaw: GHOTI

– gh as in cough
– o as in women
– ti and in action, etc.

International Phonetic Alphabet

IPA - Consonants

IPA - Vowels

IPA - Other

Speech Articulation

Making speech visible:
Melville Bell, 1867

Melville Bell’s most illustrious son

A Sensitive Mechanism for
Transmitting Vibrations

A.G. Bell’s ear phonautograph

Bliss: Words

Speech Segmentation

• The speech signal does not typically contain
breaks at word edges; worse, when breaks do
occur, they often do not coincide with perceived
word boundaries.

• Speech may incorporate cues to word
boundaries.

• These cues are language-specific.
• These cues are often unreliable, ambiguous, or

altogether missing

More Fun with Bliss:
Speech Sounds

The Problem of Invariants

• The same sounds are signaled by different
acoustic properties in different contexts

• The same acoustic properties signal
different sounds in different contexts

Another Phenomenon

Watch the movie