Obstruent voiced obstruents are common. This contrasts with sonorants, which are prototypically voiced and only rarely voiceless. Obstruent An obstruent is a speech sound such as , , or that is formed by "obstructing" airflow. Obstruents contrast with sonorants, which have no such obstruction and so resonate. All obstruents are consonants, but sonorants include both vowels and consonants. Obstruents are subdivided into plosives (oral stops), such as , with complete occlusion of the vocal tract, often followed by a release burst; fricatives, such as , with limited closure, not stopping airflow but making it turbulent; and affricates, which begin with complete
Alaryngeal speech family members" but "reported to be largely unintelligible to outsiders". Pharyngeal speech can be produced in the early stages of learning esophageal speech. However both buccal and pharyngeal speech are less clear than trained esophageal speech and "should not be regarded as a desirable or practical primary method of alaryngeal speech". A further importance is to theories of the evolution of human speech since alaryngeal speech shows that speech is not dependent entirely upon evolved anatomy as it can be created using vocal tract anatomy in an adaptive manner. Alaryngeal speech Alaryngeal speech is speech made using sources other than