While Chap. 2 was focused on the physical and biological aspects of hearing, this chapter is closer to real-life experience related to audition. The reader is first introduced to the notion of streaming for understanding the formation of an auditory object. The auditory stream is based on the relationships that one perceives between successive sounds. The sounds are grouped according to the proximity of their frequencies and how close in time they are, and this causes impressions that there is continuity, or that there are gaps, between sounds. The chapter also reveals how it is possible to localize sounds in space, either the distance of a sound source or the direction a sound is coming from. As well, the question as to why certain sounds result in an impression of music is addressed. Finally, the basic sounds of language, phonemes, are reviewed and the technical aspects related to production of speech sounds are briefly described.