That will work a lot better.
Still the timing is of course critical, and needs a lot of attention. Remember that us humans are much more flexible: if one time you hear a series of 1- and 3-second tones, you easily know which are short and which are long. If the next time it's 0.3- and 0.9-second tones, that still works fine for you. For a computer, it's a lot harder!