Voicing detection and pitch extraction from speech sounds are achieved by means of an embodiment including a plurality of bandpass filters each having sufficient passing bandwidth to pass at least two harmonics of the fundamental voice frequency, whereby each provides a signal for all voiced sounds in the form of modulated waves, the envelopes of which having a periodicity equal to the voice fundamental. This periodicity is further enhanced by means of a hard limiter. A frequency discriminator whose input is provided by the band-pass filtered output of the limiter provides a voltage waveform whose special energy distribution is utilized for discrimination between voiced and unvoiced sounds.