Unexpected artifact effect

{ translate_marker( "humming" ), translate_marker( "hums very quietly" ), {{AEP_ALL_UP, AEP_PSYSHIELD, AEP_NULL, AEP_NULL}}, {{AEP_SCHIZO, AEP_PER_DOWN, AEP_INT_DOWN, AEP_NULL}}, {{AEA_PULSE, AEA_ENTRANCE, AEA_NULL, AEA_NULL}}, {{AEA_NOISE, AEA_NOISE, AEA_SCREAM, AEA_NULL}} },

I found some “humming beads”, but they summon shadows when activated. There is no AEA_SHADOWS in “humming”. I don’t know if this is a bug or I misunderstand the code.