Chayro, any change in length that small would likely result in a slight measureable difference on an oscillosope, but it is doubtful you would ever hear it in an analog cable assuming all other parameters are identical. a digital cable is more sensitive to length as getting low jitter needs the right length (which is said to be .75 meters) is better than longer or shorter.
the exception for analog cables would be where there are impedence issues or output level issues with the gear. for instance when using passive preamps shorter interconnects (especially on the output side) are typically better sonically.
the particular cable design can also affect it's length sensitivity so it is difficult to generalize with 100% certainty.
my experience is that with RCA cables up to 2 meters sounds identical. with balanced (XLR) up to about 5 meters sounds identcal. again; the design of the gear can have an effect on this.
finally; .5 meter may create logisitical issues in the future; as it will restrict gear arraingment choices. also, it is much harder to sell .5 meter than 1 meter.