In Schaeffer's description of his 听觉训练 the second procedure of the programme of 樂/乐 研究 形态学 is a descriptive procedure of 声波 对象 once they have been identified and classed by 类型学 This description essentially consists of distinguishing features called criteria in fine 细节 their 数 being 限制 to 7 The seven morphological criteria are mass 谐/泛音 音色 动态 粒 allure melodic profile profile of mass - which are examined one by one and which are each assigned to different classes Paraphrase of Michel Chion 1983 Guide des Objets Sonores Eds Buchet/Chastel Paris 1995 translation by John Dack/Christine North