Boundary layer transition on a 7 deg half-angle cone at zero angle of attack was studied in combination with disturbance level measurements in the Hypersonic Ludwieg Tube of Technische Universität Braunschweig. The disturbance level was not only determined by means of pitot-pressure fluctuations but also by fluctuation of heat flux in the stagnationpoint using a fast-response heat-flux gauges. In addition, the second-mode instability waves in the conical boundary layer were detected by a streamwise array of surface-mounted heat flux gauges with a spectral resolution up to 1 MHz. Simultaneous measurements of the disturbance level during all runs allows a comparison of the spectral distributions of normalized wave amplitudes on the surface and in the stagnation point. Furthermore the effect of local roughness elements on the transition scenario was examined.