A novel adaptive line enhancer (ALE) structure is introduced. The adaptive filter has an autoregressive moving average (ARMA) structure which is based on classical Laguerre orthogonal functions. The frequencies and radii of the poles within the orthogonal set admit tuning. Tuning of these terms involves the use of higher-order statistics. Indeed the properties of fourth-order cumulants are exploited to aid harmonic retrieval of the sinusoids embedded in the input signal. Furthermore, adaptation of the feedforward filter parameters is straightforward since they are linearly related to the filter output. Advantages of stability, short filter length, and robustness in the presence of noise are expected. Simulation results are included to show ...