IntroductionOne of the best-known and most interesting findings in speech perception research is the “phonemic restoration phenomenon”. This is a beneficial and surprisingly utilized human ability whereby, “under certain conditions, actually missing sounds in a speech signal can be synthesized by the brain and heard clearly” (Kashino, 2006. P.318). This demonstrates the brain's sophisticated ability to understand speech in the noisy environments of everyday life. This article explores - with illustrative demonstrations - four questions regarding different aspects of phonemic restoration:1. Is phonemic restoration a conscious act? Are there conditions for its activation?2. What exactly happens during the phonemic restoration process? How is it best modeled?3. Would visual/auditory integration of a stimulus improve phonemic restoration?4. Does hearing impairment affect phonemic restoration? Basic Phenomenon The phenomenon of phonemic restoration was first demonstrated by Warren (1970). He conducted an experiment on a number of listeners by having them listen to the sentence: "The state governors met with their respective legislatures assembled in the capital." However, in the word “legislature” a cough completely masked the medial “s”. Listeners reported hearing the masked phoneme. This demonstrated that when phonemic reinstatement occurred, listeners were unable to identify the location of the masking sound in the sentence. What they received was interpreted unconsciously. In other words, the effectiveness of phonemic restoration has reached the point that listeners have not noticed. (Kashino, 2006). Surprisingly, the phonemic restoration effect was not observed when the “s” was masked by silence!Bregman (1990) ex...... middle of paper ......a0.Nakayama, K., He , Z.J., Shimojo , S., 1995. Visual surface representation: a critical link between lower-level and higher-level vision. In: Kosslyn, SM, Osherson, DN (eds.), An Invitation to Cognitive Science. The MIT Press, Cambridge, pp. 1–70. Shahin, A. &Miller, L.,2009. Multisensory integration improves phonemic restoration. J Acoust. Soc. I am. 1744-1750.Srinivansan, S. & Wang, D., 2005, A schema-based model for phonemic restoration, Speech Communication 45, 63-87Trout JD and Poser WJ1990. “Auditory and visual influences on phonemic restoration,” Lang Speech 33, 121–135. Verschuure, J. and Brocaar, M. P. 1983. “Intelligibility of interrupted meaningful and nonsense speech with and without intervening noise,” Percept. Psychophysical. 33, 232–240.Warren, R.M., 1970. Perceptual restoration of missing speech sounds. Science 167, 392– 393.