OBJECTIVE: To design and evaluate the effectiveness of a stimulus material in eliciting the N400 event related potential (ERP). DESIGN: A set of 700 semantically congruent and incongruent sentences was developed in accordance with current linguistic norms, and validated with an electroencephalography (EEG) study, in which the influence of age and gender on the N400 ERP magnitude was analysed. STUDY SAMPLE: Forty-five normal-hearing subjects (19-57 years, 21 females) participated in the EEG study. RESULTS: The stimulus material used in the EEG study elicited a robust N400 ERP, with a morphology consistent with the literature. Results also showed no statistically significant effect of age or gender on the N400 magnitude. CONCLUSIONS: The material presented in this paper constitutes the largest complete stimulus set suitable for both auditory and text-based N400 experiments. This material may help facilitate the efficient implementation of future N400 ERP studies, as well as promote standardisation and consistency across studies.