Journal of Information Organization Marko Jankovic and Dejan Ciric 13 3 2023 https://doi.org/10.6025/jio/2023/13/3/85-93 https://www.dline.info/jio/fulltext/v13n3/jiov13n3_3.pdf The sound of an instrument is often described as a “complex” sound. A complex sound can be broken down into pure (simple) sounds. In many cases, a sound can be thought of as consisting of fundamental and harmonics that provide its characteristic characteristics, depending on the number of harmonics, their distribution, their amplitude and their envelope. The human auditory system’s ability to perceive pitch is related to the harmonics in a complex sound. In this paper, we will look at how the distribution of harmonics within a complex sound influences pitch perception. We will use spectral analysis and listening tests to do this. Particular attention will be paid to the phenomenon of “missing fundamentals.”