The low natural abundance of carbon-13 results in a negligible probability of there being two adjacent carbon-13 atoms, practically eliminating carbon–carbon J-coupling. However, neighboring protons split the carbon signal according to the n+1 rule. These complex signals are simplified by the broadband proton decoupling technique. In this method, one transmitter produces radio frequency pulses that cause carbon-13 resonance. A second transmitter generates a continuous broadband of radio frequencies that cause all the protons to flip rapidly between their two energy states. So, the carbon-13 nuclei sense one average field from the protons, nullifying the spin-spin interactions. The carbon-13 signals are now decoupled from the protons, and the peaks are not split into multiplets, as seen in the proton decoupled spectrum of 1-hexanol.