Pronunciation aʃ aspire
In French the letter <h> is always silent. However, some instances of the letter do not allow elision of a preceding vowel, for instance of a preceding definite article, nor do they allow liaison. For example, le hareng (“herring”) and not *l’hareng, les harengs (“the herrings”) = le arɑ̃ and not *lez arɑ̃. The <h> in this and similar words is “aspiré”. The opposite is h muet aʃ mɥɛ. An example: l’heure (“the hour”), les heures (“the hours”) = lez œʁ.