Measurements of capacitance transients due to charge carrier emission from metastable defects in p-type hydrogenated amorphous silicon (a-Si:H) p/n junction structures, show that both holes and electrons can be metastably trapped in the p layer. At 350 K electrons and holes are emitted at the same rate defining the isokinetic temperature (Tiso) for the Meyer-Neldel rule. The enthalpy changes for hole and electron emission are 0.94 and 0.51 eV, respectively. The entropy changes for hole and electron emission are 31 and 16 Boltzmann constant, respectively. Charge emission rates are measured, for the first time, above and below Tiso. Below Tiso electrons are emitted faster than holes and above Tiso the reverse is true. These relative changes in emission rates are a direct consequence of the large entropy changes in the defect reactions. Tiso, within experimental error is the same as the H glass equilibration temperature (360 K) measured by others in p-type a-Si:H, suggesting that the defect reactions measured here are involved in H glass equilibration. Activation and deactivation of B atoms with accompanying charge emission likely govern both processes.