In West-Germanic languages, the phoneme has been found to serve as the primary unit of phonological planning. Initial evidence comes from speech error analyses indicating a large portion of phoneme-sized insertion, deletion, and substitution errors in English (Shattuck-Hufnagel and Klatt, 1979). Further evidence comes from experimental paradigms which reported faster responses in conditions with phoneme onset overlap than no overlap conditions. For example, in the picture-word interference paradigm participants named pictures faster when they were superimposed by a word that matched with the first phoneme of the picture (e.g., Schriefers et al., 1990; Meyer and Schriefers, 1991; Damian and Martin, 1999; Starreveld, 2000). Also in other production tasks, like the implicit priming paradigm (Meyer, 1991; Roelofs, 1999, 2003) and the color-object picture naming task (Damian and Dumay, 2007, 2009), overlap of the onset phoneme facilitated speech latencies. Phoneme facilitation was also found during reading aloud tasks that used priming (e.g., Forster and Davis, 1991; Kinoshita, 2000; Schiller, 2004, 2008; Timmer and Schiller, 2012; for a review see Timmer and Schiller, 2014). Taken together, the earlier consensus in the literature was that the phoneme serves as the primary unit of phonological encoding during on-line speech production. The prevalence of evidence for initial phoneme encoding in native speakers of West-Germanic languages, such as Dutch and English, has led to the assumption that the initial phoneme activation during phonological encoding is a universal feature. Dominant models of speech production include this assumption (Roelofs, 1997; Levelt et al., 1999).