The pressure spectrum of the sonic‐boomNwave is simply given byP (ω) = (2π)−12TP(T)j1(ωT/2), whereTis the boom duration,P(T) is the pressure amplitude, andj1(ωT/2) is a spherical Bessel function of the first kind and order. The effective acoustic period of theNwave is approximately32times its duration. The present formulation is a simplification of those by Crocker and Young. The spectrum formula given by Zepler and Harel is incomplete.