Zero frequency filter (ZFF) is a marginally stable infinite impulse response resonant filter at 0 Hz that is used to extract the epoch locations reliably from speech signals. However, the output of such an ideal resonator is an exponentially increasing/decreasing function of time. The trend is removed from the filtered output by subtracting the average over 1–2 pitch periods to obtain zero frequency filtered signal. Alternatively in this paper, a bounded input bounded output stable realization of ZFF is proposed for epoch extraction, where the output of such a filter is not an increasing/decreasing function of time. The advantages of using such a stable filter is that the filter output is bounded and has no precision related problem associated with the output for lengthy speech files, also, the method does not require remove trend procedure that needs initial pitch estimation. The proposed approach is evaluated using CMU-Arctic database for clean and degraded conditions. Furthermore, the method is also validated in cases of singing voice and emotional speech to demonstrate the robustness for varying pitch scenarios. The proposed method is found to be robust for wide range of chosen parameters. © 2014, Springer Science+Business Media New York.