Abstract The inverse problem here is the recovery of a spherically -symmetric wave speed υ considered in a bounded spherical region of radius b from the set of the corresponding transmission eigenvalues for which the corresponding eigenfunctions are also spherically symmetric. If the integral of 1/υ on the interval [0, b] is less than b, assuming that there exists at least one υ corresponding to the data, it is shown that υ is uniquely determined by the data consisting of such transmission eigenvalues and their multiplicities, where the multiplicity is defined as the multiplicity of the transmission eigenvalues as a zero of a key quantity.