  Noise is an important concept and its measurement and characterization has
been a flourishing area of research in contemporary mesoscopic physics. Here we
propose interaction-free measurements as a noise-detection technique, exploring
two conceptually different schemes: the coherent and the projective
realizations. These detectors consist of a qutrit whose second transition is
coupled to a resonant oscillatory field that may have noise in amplitude or
phase. For comparison, we consider a more standard detector previously
discussed in this context - a qubit coupled in a similar way to the noise
source. We find that the qutrit scheme offers clear advantages, allowing
precise detection and characterization of the noise, while the qubit does not.
Finally, we study the signature of noise correlations in the detector's signal.
