nothing bad will happen. the reason is probably because your chain is bigger than the cog and chainring. 1/8 is a larger chain than 3/32, therefor the sound comes from the slack being picked up from the oversized chain on the smaller teeth. Either way, fixed gear bikes are a bit loud, or at least generate some sort of noise from the drivetrain. The only thing that could be bad is premature wear on the gears due to the oversized chain. 1/8 will work on 3/32 but not vice versa. just get a uniform set and you'll be better off.