The acoustic theory of Barthel and Strehlow for transverse wave spacing prediction is investigated in one-dimensional detonation waves. Based on a simple model in which heat is released uniformly in the reaction zone, the cell spacings are found to be dependent upon the following parameters; the induction zone length, reaction zone length. Mach number and specific heat ratio. For high pressures, further simplification can be made when the reaction zone length is negligible compared to the induction zone length. With only the induction time data, the cell spacings were calculated for steady or overdriven detonations in H 2O 2 mixtures for various initial pressures and Ar dilution. The results are found to be in satisfactory agreement with experiments and with the more complex theoretical calculations of Barthel using the full chemical kinetics scheme for H 2O 2 reaction.