To get the best results on your personal profile we recommend you make sure you are in a quiet environment. Background noise may cause you to miss tones that you are able to hear. Of course you should also only press the button if you really heard the tone to avoid incorrect results.
If you do accidentally press the button or miss pressing the button during the process, it will not immediately lead to incorrect results. The personalization takes these possible misclicks into account by double checking the tones.