This is the study of the sound waves made by the human vocal organs for communication and how the sounds are transmitted. The sound travels through from the speaker's mouth through the air to the hearer's ear, through the form of vibrations in the air. Phoneticians can use equipment like Oscillographs and Spectographs in order to analyse things like the frequency and duration of the sound waves produced. Acoustic phonetics also looks at how articulatory and auditory phonetics link to the acoustic properties.