Class 1 Sounds - Vowels

Introduction 

The group of sounds called "Class 1 sounds" are vowels, and are distinguished as sounds that are made with an open vocal tract. These include A, E, I, O and U.

Vowels are produced when the voice is activated and the vocal tract is open. After the breath stream acquires the vibrations imparted by the vocal folds the shape of the vocal tract then produces certain changes in the sound.

Physiology

Physical characteristics of producing vowel sounds include:

  • Closure of the vocal folds
  • Contraction of muscles needed to initiate movement of the air stream
  • Activation of the voice
  • Movement of the tongue to a specific location
  • Changes in the size of the mouth opening

In all vowel sounds the vocal tract remains open while voicing occurs, while the shape of the vocal tract determines which vowel sound is produced.

Class 2 Sounds - Voiced Continuants

Introduction 

Voiced Continuants are sounds that are produced by combining voicing with constrictions in air flow through the vocal tract, with different sounds being produced by varying the place and the amount of constriction. These include L, M, N, R, V, W, and TH+ (with voice).

An example of this would be the difference in the placement of the tongue and lips when saying "LA" versus "MA". Both sounds involve voicing and a constriction of the air flow by the lips and tongue, but the placement of the latter two varies depending on the sound being produced.

Physiology 

Physical characteristics of producing Voiced Continuant sounds include:

  • Closure of the vocal folds
  • Contraction of muscles needed to initiate movement of the air stream
  • Activation of the voice
  • Movement of the tongue and lips to a specific location
  • Varying the degree on constriction for both the tongue and lips 

Class 3 Sounds - Fricative Continuants

Introduction 

Fricative Continuants are sounds that are produced by combining a lack of voicing with constrictions in air flow through the vocal tract, with different sounds being produced by varying the place and the amount of constriction. These include F, H, S, SH, and TH- (without voice).

An example of Fricative versus Voiced Continuant would be the difference between the sound TH without voice (like in the word "think") versus with voice (like in the word "the"). Both involve the same lip and tongue position, but the former does not activate the voice, while the latter does.

Physiology 

Physical characteristics of producing Fricative Continuants sounds include:

  • Closure of the vocal folds
  • Contraction of muscles needed to initiate movement of the air stream
  • Lack of voice throughout the sound
  • Movement of the tongue and lips to a specific location
  • Varying the degree on constriction for both the tongue and lips

Class 4 Sounds - Plosive Continuants

Introduction 

Plosive Continuants are sounds that are produced by a momentary stopping of the air flow through the vocal tract, followed by an (explosive) burst of air. These bursts can be either accompanied by voice, or not. These include B, D, G, K, P, and T. 

An example of a voiced plosive is the sound B in the word "bike". An example of a non-voiced plosive is the sound P in the word "paint". With both cases, the intensity of the burst of air should be minimized, with the stretch being applied to the following sound (the I in "bike" or the A in "paint").

Physiology 

Physical characteristics of producing Plosive Continuants sounds include:

  • Closure of the vocal folds
  • Contraction of muscles needed to initiate movement of the air stream
  • Momentary damming of the air stream
  • Movement of the tongue and lips to a specific location
  • Varying the degree on constriction for both the tongue and lips
  • Sudden release of the air stream, either accompanied by voice or not

Choral Speaking

Merriam Webster: ensemble speaking by a group often using various voice combinations and contrasts to bring out the meaning or tonal beauty of a passage of poetry or prose.

For someone that stutters, speaking the same words in unison as another person or group can result in fluent speech.

The use of Altered Audio Feedback (AAF) or Delayed Audio Feedback (DAF) which echoes a speakers words back to them can emulate choral speaking and improve fluency.