It has been found that a bilingual's two languages are simultaneously active, both phonologically and semantically, during language use. This activation is indicated by electrophysiological measures of performance. Not only is an individual's dominant language (L1) active when using the less dominant language (L2), but their L2 is also activated when using L1. This happens once the individual is adequately proficient in the L2. They are both active when listening to speech, reading words in either language or even planning speech in either language. Also, both languages are activated even when only one language is needed by the user.