10. An apparatus comprising: a formants modifier comprising: a receiver configured to receive Mth order linear predictive coding (LPC) coefficients representative of an input speech signal and a scale factor; a first converter configured to convert the Mth order LPC coefficients to Mth order line spectral pairs (LSPs); a multiplier configured to multiply the Mth order LSPs by the scale factor to produce scaled Mth order LSPs; an extractor configured to remove any pairs of scaled LSPs with at least one coefficient above a frequency threshold to produce a Pth order set of LSPs, where P<M; a second converter configured to convert the Pth order set of scaled LSPs to a Pth order set of LPCs; an inserter configured to pad the Pth order set of LPCs with M-P zeros; a third converter configured to convert the Pth order set of LPCs padded with zeros to a second Mth order set of LSPs; a processor configured to process the second Mth order set of LSPs and at least a third set of Mth order LSPs of another frame; and a fourth converter configured to convert the processed LSPs to processed LPCs; and a synthesizer configured to re-synthesize speech using the processed LPCs.
10. An apparatus comprising: a formants modifier comprising: a receiver configured to receive Mth order linear predictive coding (LPC) coefficients representative of an input speech signal and a scale factor; a first converter configured to convert the Mth order LPC coefficients to Mth order line spectral pairs (LSPs); a multiplier configured to multiply the Mth order LSPs by the scale factor to produce scaled Mth order LSPs; an extractor configured to remove any pairs of scaled LSPs with at least one coefficient above a frequency threshold to produce a Pth order set of LSPs, where P<M; a second converter configured to convert the Pth order set of scaled LSPs to a Pth order set of LPCs; an inserter configured to pad the Pth order set of LPCs with M-P zeros; a third converter configured to convert the Pth order set of LPCs padded with zeros to a second Mth order set of LSPs; a processor configured to process the second Mth order set of LSPs and at least a third set of Mth order LSPs of another frame; and a fourth converter configured to convert the processed LSPs to processed LPCs; and a synthesizer configured to re-synthesize speech using the processed LPCs. 21. The apparatus of claim 10 , further comprising a user interface configured to receive inputs to control the scale factor.