The Expressive Transducer, and What Babies Hear

When breathing for life, inhalation is active involving many muscles and exhalation is passive.

When breathing for speech, exhalation is highly controlled, requiring special neurological circuitry which humans posses.

The Generator is a mechanism to produce sound , which is required for speech.

There are two passages leading from the oral cavity--one for food (Esophagus) and one for air (Trachea).

If liquid or food gets down the wrong tube (the Trachea) we may get pneumonia or worse yet, quick asphyxiation.

The Larynx (not to be pronounced "Larnyx") is a valve system at the top of the Trachea to keep food out.

In the Larynx, the vocal folds open and close to let air pass and to keep food from falling down the Trachea.

When the vocal folds are shut and air if forced through, they will vibrate and produce a sound.

The only changes in sound we can make at the level of the larynx is to raise and lower the pitch and loudness.

When the vocal folds are abused they may swell, which causes a drop in the pitch of the voice.

The greatest threat to the health of the vocal folds is smoking.

A person who has his/her larynx removed is called a laryngectomee.

A laryngectomee has no voice, and must use an artificial larynx or esophageal speech to communicate.

Esophageal speech takes time and effort to learn, and the artificial larynx sounds mechanical.

Juvenile Pappiloma is an aggressive growth on the larynx of some young children that requires medical attention.

A series of resonating air chambers above the larynx alter the overtones to create the human voice.

The Pharynx and the Nasal Cavity are two resonating cavities that shape the sound produced by the Larynx.

Only three sounds in English use Nasal Resonance.: "m," "n," and "ng."

The Oral Cavity it the major Modulator of the three resonating cavities.

The Oral Cavity can produce phonemes with a minimal expenditure of movement and energy.

Actually, speech is not a series of discrete phonemes, but a continuous modulated flow of vocalized sound.

Babies do not perceive phonemes, but instead can hear all of the distinctive features that build the phonemes of every language.

Voice Onset Time is a good example of a distinctive feature that babies perceive, but we as adults may not.

It is advantageous to have speakers of other languages talk to babies who are not high risks for language delay.

The Place of Constriction of the air flow through the vocal tract is one distinctive feature for consonants.

The place of constriction can be described in terms of locations proceeding from front to back in the vocal tract.

The baby is capable of perceiving the constriction boundaries of English and all other languages.

In vocalizations, back consonants appear first during the reflexive stages, but front consonants appear first in the voluntary stages.

The Manner of Articulation is a second Distinctive Feature for Consonants.

The addition of a tone from the Larynx (+Voicing) to the noise of a consonant provides a third distinctive feature.

Nasality, a fourth distinctive feature of consonants, is used in only 3 phonemes in English: "M," "N," and "Ng."



  • Nasality: Unlike French which includes nasal resonance in some vowels, no vowels in English include it. No consonants can be made either nasality with the exception these three: "M," "N," and "Ng."


    The place of articulation for vowels refers to the arching action of the tongue to produce front, mid or back vowels.

    In vocalizations, front vowels appear first during the reflexive stages, but back vowels appear first in the voluntary stages.

    The tongue raises and lowers to produce an array of front and back vowels.

    The position of the jaw will drop for low vowels to facilitate the movement of the tongue.

    For some vowels, the tongue is more relaxed than for others.

    Lip rounding is more essential for lip reading than for sound production.

    Lip rounding is an important visual component in the perception of speech.

    The key to good phonemic development is for the parents to spend much time talking to and around their baby.

  • These are just a few of the distinctive features (building blocks of phonemes) that the baby is equipped to hear at birth.

  • It remains for the parents to provide the materials (speech sounds) for the child to maintain and strengthen these listening skills. The child who sits alone for long hours in a crib will be at a disadvantage relative to the child who has doting parents hovering about and talking to and chatting about their child.

  • And if one of the parents is speaking another language, better yet for the baby's developing phonemic structure.

    Now we are ready to look at the Receptive Transducer for the Auditory Modality- the Ear and see how is interfaces with sound to make speech and language possible, or how it fails to interface and how this impacts on speech and language.