IEM can refer to: I.E.M. (album) Inborn error of metabolism. In-ear monitors, devices used by musicians, audio engineers and audiophiles to listen to music. Incredible Expanding Mindfuck (Music) Information Engineering Methodology. Institute of Electronic Music and Acoustics (Institut für Elektronische Musik und Akustik), part of the University of Music and Performing Arts, Graz. Institute of Engineering and Management. Integrated Enterprise Modeling. Institute of Engineering in Medicine, part of the University of California, San Diego.
https://en.wikipedia.org/wiki/IEM