The state of a flame in a gas turbine combustor is acoustically monitored using a single dynamic pressure sensor within the combustor. A dynamic pressure sensor output signal is received from the single sensor and is processed to determine a flame status. The signal is processed by performing an autocorrelation operation to identify time-separated portions of the signal and to determine that the time-separated portions of the signal include portions indicative of acoustic oscillations emitted by the flame in the gas turbine engine combustor and received directly by the single acoustic sensor, and portions indicative of reflections.