 The volume of the voices are typically only estimated and not actually measured with sound level meters, giving a chair enough plausible deniability to falsify the result if they disagree with it; even if such a vote can be objectively quantified in terms of decibels, the method gives an unfair advantage to those who have louder voices.The need to make an audible signal also compromises any situation in which a secret ballot may be desired.The method is suitable in most cases where unanimity is required.