GUSMASK_VOICE_IRQ
bus_space_write_1(iot, ioh2, GUS_DATA_HIGH, sc->sc_voc[voice].voccntl & ~(GUSMASK_VOICE_IRQ));
sc->sc_voc[voice].voccntl |= GUSMASK_VOICE_IRQ;
sc->sc_voc[voice].voccntl &= ~GUSMASK_VOICE_IRQ;
sc->sc_voc[voice].voccntl &= ~(GUSMASK_VOICE_IRQ);