The PhD investigates the creation of closeness and immediacy through composition, exploring the processes of capturing, processing and composing sound materials, their spatialisation both during production and performance, and the sound materials' contexts. It is suggested that closeness can be understood spatially, temporally and in addition as being familiar with sounds and musical languages; whereas immediacy adds the meaning of being involved at some level in the shaping or decoding of the meaning of sounds of a composition. In that sense closeness and immediacy together form entry-points for the listener to make him/her become engaged in the compositional narrative. Seven original acousmatic and mixed media works are presented in the portfolio. These are stone and metal, empty rooms, weave/unravel, skalna, pulses, beeps and triptych. The pieces rely on found sounds and their referential qualities, with both informing the compositional methodologies. They also borrow elements from soundscape composition, electronic music and film music. Over the development of the portfolio the inclusion of elements of other genres of music became a valuable source of inspiration and shaped the compositional methodology which lead to the development of a unique, personal style of composition. Three of the PhD’s compositions – pulses, beeps and triptych – investigate the musical opportunities of an acousmatic take on stems to improve the flexibility and perceived depth of spatialisation. The spatial layers of the compositions are split into parts of a soundfile. These parts can be mapped according to specific rules to the number of loudspeakers available. The portfolio pieces demonstrate that composing in spatial stems enhances spatial depth as close and distant sounds can be reproduced independently of each other on dedicated loudspeakers at the same time. The sounds of the distant loudspeakers merge with the acoustic properties of the performance space and therefore assist in making the composed spaces credible. In addition to the compositions, one original software tools are presented in the portfolio (PLib), as well as a substantial contribution to an existing tool (MANTIS Diffusion System). They aim to facilitate the production and performance of electroacoustic music. Their application and potential is briefly discussed in the commentary.