I obtained my Ph.D. in Astronomy in June 2014, at the University of Cape Town, under the general guidance of Prof. W. J. G. de Blok. The thesis title was "Interstellar medium properties and star formation in nearby galaxies". My thesis received an A rating from all three external examiners. My subsequent peer-reviewed papers have been valuable for theoretical models that assess the role and origin of turbulence in the interstellar medium. The thesis made use of high-resolution interferometric observations of neutral atomic hydrogen (HI) gas in nearby galaxies to measure with high precision fundamental parameters, relevant for star formation studies. I achieved this robust measurement by reducing the effects of noise using a spectral-line stacking technique.