determined by the position of the movable parts—­the tongue and the lips.  As the tongue is raised or lowered, retracted or brought forward, held tense or lax, and as the lips are pursed ("rounded”) in varying degree or allowed to keep their position of rest, a large number of distinct qualities result.  These oral qualities are the vowels.  In theory their number is infinite, in practice the ear can differentiate only a limited, yet a surprisingly large, number of resonance positions.  Vowels, whether nasalized or not, are normally voiced sounds; in not a few languages, however, “voiceless vowels"[18] also occur.

[Footnote 18:  These may be also defined as free unvoiced breath with varying vocalic timbres.  In the long Paiute word quoted on page 31 the first u and the final ue are pronounced without voice.]

[Transcriber’s note:  Footnote 18 refers to line 1014.]

The remaining oral sounds are generally grouped together as “consonants.”  In them the stream of breath is interfered with in some way, so that a lesser resonance results, and a sharper, more incisive quality of tone.  There are four main types of articulation generally recognized within the consonantal group of sounds.  The breath may be completely stopped for a moment at some definite point in the oral cavity.  Sounds so produced, like t or d or p, are known as “stops” or “explosives."[19] Or the breath may be continuously obstructed through a narrow passage, not entirely checked.  Examples of such “spirants” or “fricatives,” as they are called, are s and z and y.  The third class of consonants, the “laterals,” are semi-stopped.  There is a true stoppage at the central point of articulation, but the breath is allowed to escape through the two side passages or through one of them.  Our English d, for instance, may be readily transformed into l, which has the voicing and the position of d, merely by depressing the sides of the tongue on either side of the point of contact sufficiently to allow the breath to come through.  Laterals are possible in many distinct positions.  They may be unvoiced (the Welsh ll is an example) as well as voiced.  Finally, the stoppage of the breath may be rapidly intermittent; in other words, the active organ of contact—­generally the point of the tongue, less often the uvula[20]—­may be made to vibrate against or near the point of contact.  These sounds are the “trills” or “rolled consonants,” of which the normal English r is a none too typical example.  They are well developed in many languages, however, generally in voiced form, sometimes, as in Welsh and Paiute, in unvoiced form as well.

[Footnote 19:  Nasalized stops, say m or n, can naturally not be truly “stopped,” as there is no way of checking the stream of breath in the nose by a definite articulation.]

[Footnote 20:  The lips also may theoretically so articulate.  “Labial trills,” however, are certainly rare in natural speech.]