Obstruent 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 occlusion but then release into a fricative-like release, such as . Obstruents are prototypically voiceless, but
Complete Vocal Institute to detect the various vocal modes. Currently (2012) Cathrine Sadolin and Julian McGlashan are researching the terminology used in describing singing and the use of the voice. Together with sound specialist Eddy B. Brixen (from DPA) and EBB-consult, there is ongoing research in making spectral analysis of the sound spectrum, the voice produces with the various modes. In addition to testing the techniques in a scientific way another goal is that an outsider will be able to identify the different voice modes on a purely objective basis, without prior knowledge of singing. Complete Vocal Institute Complete Vocal Institute (often abbreviated