Abstract: Signal processing device comprising: a signal analyser (7) for analysing a received signal into the subband domain; a first signal path (10) and a second signal path (11), the first signal path (10) being decoupled from the second signal path (11), whereby the first signal path (10) and the second signal path (11) are arranged to pass the received signal; only the first signal path (10) includes automatic gain control (3), the first signal path (10) further includes one or more speech metric functions (4, 5, 6) to determine estimated gain functions therein, the signal in the first signal path being passed from the automatic gain control (3) to the one or more speech metric functions (4, 5, 6) to enable determination of the estimated gain functions, the estimated gain functions determined by the one or more speech metric functions being combined to generate an overall gain function which is applied (9) to the signal (14) in the second signal path (11) to generate an enhanced signal; and a signal synthesiser (8