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
Complete Vocal Institute sounds or had problems with their voice. The work formed the basis for the techniques Complete Vocal Institute currently uses and Cathrine Sadolin has continued the voice research together with physicians and acousticians. Cathrine Sadolin has been invited to speak in the voice conferences in Europe and USA since 1996. In 2007, she started to collaborate with consultant ENT Surgeon Julian McGlashan from Nottingham University Hospital. Their first joint research study was published in February 2007 on auditive research, where speech therapists had to determine which voice modes was used by listening to song samples. After that they cooperated to