Browsing by Subject "äänen muodostus"

Human larynx is located lower compared to the location of larynx in closely related species. The descended larynx is related to ability to speak and has been considered unique to human. The descent of the larynx enables the two-tube configuration of the vocal tract with equally long horizontal and vertical parts. This configuration is optimal for vocalization. However, because of the descended larynx, human adults have lost the ability to swallow while eating. This ability is found in most mammals and also in human infants. In this literature review, I will answer the question of how does the descended larynx affect human voice by referring to six systematically retrieved articles. The aim of this study is to describe the descended larynx from anatomical and evolutionary perspectives and thus increase logopedical knowledge. The studies referred in this review showed that descended larynx is also found in many other mammals besides human. This indicates the non-phonetic function of lowered larynx. However, because of the descended larynx, the human vocal tract is optimal for speech and for producing as large range of speech sounds as possible. Thus, descended larynx may have created evolutionary advantage by enabling larger repertoire of signals. In addition, studies show that the descended larynx is related to sexual dimorphism. One indication of human voice sexual dimorphism is the ability of males to produce lower formats than females.