Studying for an exam while listening to music is not smart，（33）___ background music can reduce your ability to perform memory tasks，new research has found．

Study participants were asked to recall a list of eight letters in the order they （34）___（present）．They did this while in five different sound environments：quiet surroundings； music they liked； music they disliked； changing state （an order of random digits）； and steady state （an order of steady digits such as"3，3，3，3"）．

The participants'recall ability was the poorest when listening to music，regardless of （35）___ they liked or disliked it，and in changing-state conditions．（36）___（accurate） recall occurred when participants performed the task in steady-state environments，according to the study （37）___（publish） online in the journal Applied Cognitive Psychology．

"It is the sound variation in the music and changing state （38）___ reduces the ability to recall the order of items within the presented list，"explained the leading researcher Nick Perham，（39）___ is a lecturer in the School of Psychology at the University of Wales Institute in Cardiff，in a news release from the journal's publisher．

When performing （40）___ challenging mental task，do it in silence，Perham recommended．