acoustics - the study of the physical properties of sound

speech sound, phone, sound - (phonetics) an individual sound unit of speech without concern as to whether or not it is a phoneme of some language

infection - (phonetics) the alteration of a speech sound under the influence of a neighboring sound

assimilate - become similar in sound; "The nasal assimialates to the following consonant"

dissimilate - become dissimilar by changing the sound qualities; "These consonants dissimilate"

shift - change phonetically as part of a systematic historical change; "Grimm showed how the consonants shifted"

long - of speech sounds (especially vowels) of relatively long duration (as e.g. the English vowel sounds in `bate', `beat', `bite', `boat', `boot')

short - of speech sounds (especially vowels) of relatively short duration (as e.g. the English vowel sounds in `pat', `pet', `pit', `pot', putt')

tense - pronounced with relatively tense tongue muscles (e.g., the vowel sound in `beat')

lax - pronounced with muscles relatively relaxed (e.g., the vowel sound in `bet')