[Landmarks of physiological development of the voice in childhood and adolescense (Part 1)].

The area of the functioning of the voice is a fundamental element of human communication apart from language, speaking, hearing and perceiving. Detailed knowledge of normal vocal development is a prerequisite for the diagnosis and therapy of vocal dysfunctions among children and adolescents by means of methods suitable for their age and their stages of development. In an overview, the landmarks of physiological development with normal value ranges relevant to practice are presented--from the newborn baby's first cry up to the age of young adults. The effects of various degrees of vocal activity on the part of children and adolescents on the parameters of vocal capacity and quality are taken into account, as well as the relationship between physical and vocal development. Furthermore, an overview of diagnostic methods suitable for this age group is given. Specialists for ENT and for Phoniatrics and Pediatric Audiology should be able to assess suitability for increased vocal activity and to care for vocal development during the vulnerable phase of the voice change. Manifold socio-cultural and pedagogical influences are already possible in early childhood and throughout the phase of the "voice in growth". They should be taken advantage of prophylactically--also with regard to the learning of physiological vocal behavior as a prerequisite for dealing with possible subsequent strain in vocally intensive professions. In the following second part of this publication, the fundamentals described here are applied to diagnostics and therapy of vocal dysfunctions in this age group by means of methods suitable for this stage of development.