downgearing cause hiccups ?

hi when i downgear or do something that makes a big change of sound volume the ac game then it hiccups.
on board soundcard.

would a external soundcard help?
or is it something else ?

Gigabyte GA-Z97X-GAMING 3
Intel Core i5 4690K 3,5GHz

ASUS GeForce STRIX GTX 750Ti 2GB PhysX
PCI-Express 3.0, "DirectCU II OC", GDDR5, DL-DVI-I, DP, HDMI
8 gb
samsung 840 256 gb
750 w...

downgearing cause hiccups ?