1. A computer implemented method to authorize access to a computer function, comprising the steps of: receiving a request to access a computer function from a requesting computer; generating a computer generated validation test and an expected response, wherein said validation test comprises a series of sounds presented at various intervals, wherein at least one sound in said series of sounds is a validation sound; presenting said computer generated validation test to the requesting computer; receiving an input from said requesting computer in response to the validation test presented to said requesting computer; determining whether the input corresponds to the expected response; and allowing access to the computer function if the input corresponds to the expected response.