does your engine try to stall out?? and is the noise prevalent while idling too, if yes then the driveplate springs are shot and you need a new one (its the entire flywheel) - this trans does not use a torque convertor.
The sound also can be due the first clutch going bad, it can be recalibrated by Honda in about 5 minutes - but if that does not help and you never changed fluid in the system you most probably would need to o/h the trans - $$$$$$$$$$$$$$$$$$$$$$$$$$
the operating temperature of this transmission can easily reach 120*C when under load, The CVT fluid takes a solid beating at that time and hence needs to be changed out first at 50,000 kms and later on every 40,000 kms.