A radio, comprising: a digital vocoder having a predetermined data frame sampling rate; at least one processor for enhancing a modulation index of a predetermined high modulation rate sound event, the at least one processor detecting energy nulls of the predetermined high modulation rate sound event in a digitized speech stream, wherein the at least one processor comprises: a pre-vocoder processor comprising a frame shifter for shifting a data frame of the digitized speech stream forward or backward in time relative to the vocoder frame sampling time to coincide with detected energy nulls; and wherein the frame shifter further comprises: a voice frame energy calculator for calculating voice frame energy at a higher data frame sampling rate than the vocoder; a differential energy calculator to determine inter-frame differences; an energy difference classifier defining a state machine; the state machine identifying and locating the nulls; and a buffer for shifting the data frame of the digitized speech stream backward or forwards based on the identified and detected energy nulls. a digital vocoder having a predetermined data frame sampling rate; at least one processor for enhancing a modulation index of a predetermined high modulation rate sound event, the at least one processor detecting energy nulls of the predetermined high modulation rate sound event in a digitized speech stream, wherein the at least one processor comprises: a pre-vocoder processor comprising a frame shifter for shifting a data frame of the digitized speech stream forward or backward in time relative to the vocoder frame sampling time to coincide with detected energy nulls; and wherein the frame shifter further comprises: a voice frame energy calculator for calculating voice frame energy at a higher data frame sampling rate than the vocoder; a differential energy calculator to determine inter-frame differences; an energy difference classifier defining a state machine; the state machine identifying and locating the nulls; and a buffer for shifting the data frame of the digitized speech stream backward or forwards based on the identified and detected energy nulls. a pre-vocoder processor comprising a frame shifter for shifting a data frame of the digitized speech stream forward or backward in time relative to the vocoder frame sampling time to coincide with detected energy nulls; and wherein the frame shifter further comprises: a voice frame energy calculator for calculating voice frame energy at a higher data frame sampling rate than the vocoder; a differential energy calculator to determine inter-frame differences; an energy difference classifier defining a state machine; the state machine identifying and locating the nulls; and a buffer for shifting the data frame of the digitized speech stream backward or forwards based on the identified and detected energy nulls. a voice frame energy calculator for calculating voice frame energy at a higher data frame sampling rate than the vocoder; a differential energy calculator to determine inter-frame differences; an energy difference classifier defining a state machine; the state machine identifying and locating the nulls; and a buffer for shifting the data frame of the digitized speech stream backward or forwards based on the identified and detected energy nulls.