RESUMO
Birdsong overlapping may either indicate communicative interaction between birds or be a simple coincidence. We developed a program that allowed us to mathematically modulate the independent singing of birds with a given level of song rate. This permitted us to statistically evaluate whether song overlapping is a random coincidence or real acoustic interactions between birds. Analysis of automatic recording (Song Meter SM4) of singing detected the cases of reliable acoustic interactions between both conspecific and heterospecific individuals. They account for 6% of the total singing time. The most numerous and actively singing chaffinches (in the case of singing of several individuals) suppress the singing of other species. The singing of a single chaffinch, on the other hand, can provoke the singing of other species, involving previously silent neighbors in song duels. It is possible that it is the acoustic interactions that are responsible for maintaining the structure of the population at the end of the breeding season.
Assuntos
Acústica , Vocalização Animal , Animais , Aves , Humanos , Estações do AnoRESUMO
The paper analyzes voice disturbances, their causes and specific features in teachers based on the questionnaires filled by 934 general educational school teachers. The teachers have been found to associate voice disturbances not only with changes in the voice timbre, but with different subjective feelings that make their professional activity difficult. The major factors that cause voice disturbances are the voice overloads that differ in teachers of different specialities, their inability to use the voice, psychoemotional stresses, and frequent colds, as well as a combination of several factors. The incidence of vocal apparatus diseases does not tend to decrease, which makes it necessary to implement combined medical and pedagogical prophylactic measures to prevent dysphonia.