Clicking/Ticking Noise while Accelerating

hi sirs,

lately may na-notice ako ng clicking/ticking noise coming from the front of the car while stepping on the gas pedal. although di naman ganun kalakas maririning lang pag off ang radyo. when you rev the engine in neutral wala naman yung ingay pag umaandar lang talaga. yung clicking/ticking occurs driving straight and wala pag naliko. any ideas? car is honda city 04.

tia :)