In the present study, the effects of fluid-structure interaction (FSI) on the trailingedge noise are numerically investigated, particularly for the cases of wake instability and Karman vortex shedding. The trailing-edge is modelled as a flat plate with an elastic cantilever end and its flow-induced vibration is solved by an eigenmode analysis with the Galerkin method. The FSI analysis is conducted in a fully coupled manner with direct numerical simulation (DNS) of the flow and sound. Computed solutions for the wake instability show that when the first-eigenmode natural frequency (?n) of the cantilever is close to be resonant with the wake characteristic frequency (?c), the sound pressure level (SPL) is significantly reduced by -20 dB or increased by +15 dB, depending on the ratio of ?n/?c. For Karman vortex shedding, the flow and acoustic details are somewhat different but FSI also has considerable impacts on the SPL and directivity, if ?n is close to ?c.