System and method for modifying speech signals

A system for processing a speech signal, comprising:

• means for analyzing a received, narrowband signal to determine synthetic upper band content;
• means for reproducing a lower band of the speech signal using the received, narrowband signal;
• and
• means for combining the reproduced lower band with the determined, synthetic upper band to produce a wideband speech signal having a synthesized component.

A system for processing a narrowband speech signal at a receiver, comprising:

• an upsampler that receives the narrowband speech signal and increases the sampling frequency to generate an output signal having an increased frequency spectrum;
• a parametric spectral analysis module that receives the output signal from the upsampler and analyzes the output signal to generate parameters associated with a speech model and a residual error signal;
• a pitch decision module that receives the residual error signal from the parametric spectral analysis module and generates a pitch signal that represents the pitch of the speech signal and an indicator signal that indicates whether the speech signal represents voiced speech or unvoiced speech;
• a residual extender and copy module that receives and processes the residual error signal and the pitch signal to generate a synthetic upper band signal component.