1. A device for assessing a quality class of an object to be tested, comprising: a unit for detecting an acoustic non-voice test signal from the object to be tested; a unit for providing a stochastic Markov model including states and transitions between states on the basis of reference measurements of objects of known quality classes, wherein, in the stochastic Markov model, a single probability density distribution is associated with each state, and wherein several states have transitions from a common predecessor state; a unit for evaluating the test signal using the stochastic Markov model; and a unit for associating the object to be tested with a quality class based on the evaluation of the test signal.