Фонетика английского языка

1 Phonemes and allophones
Speech sounds are vibrations that travel through a medium (usually air) by displacing the molecules of this medium. Depending on the consistency of the given medium, the sounds travel at different speeds and have varying intensities. This is why we sound differently when we speak under normal circumstances from when we try to talk under water and also why it is completely impossible for speech sounds to travel through a vacuum. Speech sounds travel in the shape of waves, similar to the ripples that arise when we throw an object – such as a stone – into the water. The degree of displacement corresponds to the height (amplitude) of the wave. Amplitude in sound waves corresponds to intensity – measured in decibel, or dB for short – which, in turn, corresponds to our subjective impression of loudness.