The primary purpose of this experiment was to systematically investigate the actions of the intrinsic muscles of the larynx during the production of voiced and voiceless consonants. Generally speaking, computer-averaged EMG curves for the laryngeal muscles showed participation of the posterior cricoarytenoid for voiceless consonants and suppression for voiced consonants. The reciprocal pattern was found for the interarytenoid muscle. Similar reciprocal patterns were evident along the timing dimension. These results are discussed in terms of recently proposed laryngeal feature systems.