Abstract: A system, device and method for assessing a fit quality of an earpiece while in use in a noisy environment. The earpiece having an external microphone for capturing an outer-ear audio signal and an internal microphone for capturing an inner-ear audio signal. The fit quality being assessed by estimating a filter according to the captured inner-ear and outer-ear audio signals, and determining a fit quality according to identified coefficients of the estimated filter. A system, device and method for assessing a seal quality of an earpiece while in use in a quiet environment. The earpiece having a loudspeaker for emitting a sound stimulus towards the ear canal and an internal microphone for capturing an audio signal inside the ear canal. The seal quality being assessed by estimating a transfer function according the emitted and captured sound stimulus, and determining at least one seal-quality indicator according to a signal magnitude of the transfer function.