高低口音（英语：Pitch accent），是一种口音。在高低口音语言里，一个词里的每个音节的音调取决于该音节在词里出现的位置。而声调语言中，每个音节有自己固定的声调，它的声调和它在词里出现的位置无关。世界上很多语言（如日语、吴语等）都含有的高低口音系统（另一种是轻重口音）。

比如对于同样都只有低高两调之分的音高重音语言和声调语言，一个双音节词[aba]， 在音高重音语言里只有两种可能的音调：[ába]或[abá]。而在声调语言中可能有四种：低低调[àbà]、高高调[ábá]、高低调[ábà]、低高调 [àbá]。

Pitch accent is a feature of certain languages whereby variations in pitch (linguistic tones) can be used to differentiate words, but where the potentially distinctive tones are restricted to only one or two syllables within a word, as opposed to fully tonal languages like Standard Chinese, where each syllable can have an independent tone. In a pitch accent language, the syllable with phonemic tone is typically one that is acoustically prominent (stressed). Also many words may not be marked for tone at all.