Here some information about it: 1) "Brett Manning is an American singer and vocal coach noted for a self-proclaimed five-octave voice, which he alleges makes use of the high-range whistle register. He worked under the guidance of numerous vocal coaches until he met with vocal coach Seth Riggs, developer of the "Speech Level Singing" method of instruction. He later became a teacher, operating as a Riggs associate for more than ten years." Source: http://en.wikipedia.org/wiki/Brett_Manning 2) "Speech Level Singing is founded on the concept of singing in the same comfortable manner as you speak. The use of the outer muscles is eliminated and the vocal cords are allowed to function in their natural manner by shortening and thinning for the higher notes. The larynx stays in a relaxed position throughout the entire range of the singer." Source and sample exercises: http://www.johnhenny.com/products.html 3) Further information: http://www.goodrichvocal.com/speechlevel/speech_level_singing.htm Here also some sample lessons: http://www.goodrichvocal.com/education/voicelesson_men.htm http://www.goodrichvocal.com/education/voicelesson_women.htm http://www.speechlevelsinging.com/ http://www.sethriggs.com/ http://www.myvoiceteacher.com/ http://www.davestroud.com/ http://www.become-a-singing-master.com/speech-level-singing.html http://www.voiceteacher.com/speech_level.html http://en.wikipedia.org/wiki/Vocal_registration#Speaking_Voice_.28Chest.29