Time scale modification of speech signals

Claim 1

A method of modifying the time sacle of speech signals, said signals representing a wave form having a given pitch period and comprising a sequence of samples, the method comprising the steps of: (a) storing said sequence of samples in a memory; (b) retrieving said stored samples from said memory; (c) estimating a number of said retrieved samples that constitutes a pitch period of said signals; (d) reproducing a plurality of gorups of said retrieved samples in the form of audible speech with each of said groups consisting of said estimated number of samples; (e) combining a first group of said retrieved samples with a second group of said retrieved samples to form a combined group of said estimated number of samples, said second group immediately following said first group in said sequence of samples; and (f) reproducing said combined group in the form of audible speech.

Claim 2

A method of modifying the time sacle of speech signals, said signals representing a wave form having a given pitch period and comprising a sequence of samples, the method comprising the steps of: (a) storing said sequence of samples in a memory; (b) retrieving said stored samples from said memory; (c) estimating a number of said retrieved samples that constitutes a pitch period of said signals; (d) reproducing a plurality of gorups of said retrieved samples in the form of audible speech with each of said groups consisting of said estimated number of samples; (e) combining a first group of said retrieved samples with a second group of said retrieved samples to form a combined group of said estimated number of samples, said second group immediately following said first group in said sequence of samples; and (f) reproducing said combined group in the form of audible speech.

Claim 7

A method of modifying the time scale of speech signals, said signals representing a wave form having a given pitch period and comprising a sequence of samples, the method comprising the steps of: (a) storing said sequence of samples in a memory; (b) selecting a scaling rate for reproduction of said signals from among a predetermined plurality of scaling rates; and (c) reproducign said signals from said stored sequence fo samples in audible form in accordance with said selected scaling rate; wherien, if said selected scaling rate is other than 1.0, said step (c) comprises the substeps of: (i) estimating a number of said samples that constitutes a pitch period of said signals; (ii) combining a first group of said samples with a second group of said samples to form a combined group of said estimated number of samples, said second group immediately following said first group in said sequence of samples; and (iii) reproducing said combined group in the form of audible speech.

Claim 8

A method of modifying the time scale of speech signals, said signals representing a wave form having a given pitch period and comprising a sequence of samples, the method comprising the steps of: (a) storing said sequence of samples in a memory; (b) selecting a scaling rate for reproduction of said signals from among a predetermined plurality of scaling rates; and (c) reproducign said signals from said stored sequence fo samples in audible form in accordance with said selected scaling rate; wherien, if said selected scaling rate is other than 1.0, said step (c) comprises the substeps of: (i) estimating a number of said samples that constitutes a pitch period of said signals; (ii) combining a first group of said samples with a second group of said samples to form a combined group of said estimated number of samples, said second group immediately following said first group in said sequence of samples; and (iii) reproducing said combined group in the form of audible speech.

Claim 13

A method of modifying the time scale of speech signals, said signals representing a wave form having a given pitch period and comprising a sequencde of samples, the method comprising the steps of: (a) storing said sequence of samples in memory; (b) requesting reproduction of said signals; (c) selecting a scaling rate for reproduction of said signals from among a predetermined plurality of scaling rates; (d) estimating a number of said samples that constitutes a pitch period of said stored signals; and (e) reproducing said signals from said stored sequence of samples in audible form in accordance with said selected scaling rate; the method further comprising teh following steps is said selected scaling rate exceeds 1.0: (f) reproducing in audible form at a scaling rate of 1.0 a seuqence of groups of said samples, said sequence consisting of n groups of samples, n being a positive integer and being a function of said selected scaling rate, each of said groups consisting of a number of sequential samples, said number being equal to said estimated number, said sequence comprising a last group; (g) combining said last group with another group of samples, to form a combined group, said another group also consisting of said estimated number of samples, said another group immediately following said last group; (h) reproducign said combined group in the form of audible sound; and (i) repeating steps (f), (g) and (h) until said requested reproduction is complete; the method further comprising the following steps if said selected scaling rate is less than 1.0: (j) reproducing in audible form at a scaling rate of 1.0 a sequence of groups of said samples, said sequence consisting of m groups of samples, m being a positive integer and being a function of said selected scaling rate, each of said groups consisting of a number of sequential samples, said number being equal to said estimated number, said sequence comprising a last group; (k) combining a first following group with a second following group to form a combined group of samples, said first and second groups each consisting of said estimated number of samples, said first group immediately following said last group, said second group immediately following said first group; (l) not reproducing said first and second groups and reproducing said combined group in the form of audible sound in place of said first and second groups; and (m) repeating steps (j), (k) and (l) until said requested reproduction is complete.

Claim 14

A method of modifying the time scale of speech signals, said signals representing a wave form having a given pitch period and comprising a sequencde of samples, the method comprising the steps of: (a) storing said sequence of samples in memory; (b) requesting reproduction of said signals; (c) selecting a scaling rate for reproduction of said signals from among a predetermined plurality of scaling rates; (d) estimating a number of said samples that constitutes a pitch period of said stored signals; and (e) reproducing said signals from said stored sequence of samples in audible form in accordance with said selected scaling rate; the method further comprising teh following steps is said selected scaling rate exceeds 1.0: (f) reproducing in audible form at a scaling rate of 1.0 a seuqence of groups of said samples, said sequence consisting of n groups of samples, n being a positive integer and being a function of said selected scaling rate, each of said groups consisting of a number of sequential samples, said number being equal to said estimated number, said sequence comprising a last group; (g) combining said last group with another group of samples, to form a combined group, said another group also consisting of said estimated number of samples, said another group immediately following said last group; (h) reproducign said combined group in the form of audible sound; and (i) repeating steps (f), (g) and (h) until said requested reproduction is complete; the method further comprising the following steps if said selected scaling rate is less than 1.0: (j) reproducing in audible form at a scaling rate of 1.0 a sequence of groups of said samples, said sequence consisting of m groups of samples, m being a positive integer and being a function of said selected scaling rate, each of said groups consisting of a number of sequential samples, said number being equal to said estimated number, said sequence comprising a last group; (k) combining a first following group with a second following group to form a combined group of samples, said first and second groups each consisting of said estimated number of samples, said first group immediately following said last group, said second group immediately following said first group; (l) not reproducing said first and second groups and reproducing said combined group in the form of audible sound in place of said first and second groups; and (m) repeating steps (j), (k) and (l) until said requested reproduction is complete.

Claim 20

An apparatus for storing and reproducing speech signals, comprising: a memory; means for storing said signals in said memory in the form ofa sequence of samples; means for retrieving said samples from said memory; means for reproducing speech signals in the form of audible speech; and a processor connected to said memory, said storing means, said retrieving means and said reproducing means, said processor being programmed to: (a) cause said storing means to store said signals in said memory; (b) cause said retrieving means to retrieve said samples from said memory; (c) estimate a number of said retrieved samples that constitutes a pitch period of said signals; (d) cause said reproducing means to reproduce a group of said retrieved samples, said group consisting of a number of samples, said number being equal to said estimated number; (e) after step (d), combine a first group of said retrieved samples with a second group of said retrieved samples to form a combined group, said first group and second group each consisting of a same number of sequential samples, said same number being equal to said estimated number, said second group immediately following said first group in said sequence of samples; and (f) cause said reproducing means to reproduce said combiend group.

Claim 21

An apparatus for storing and reproducing speech signals, comprising: a memory; means for storing said signals in said memory in the form ofa sequence of samples; means for retrieving said samples from said memory; means for reproducing speech signals in the form of audible speech; and a processor connected to said memory, said storing means, said retrieving means and said reproducing means, said processor being programmed to: (a) cause said storing means to store said signals in said memory; (b) cause said retrieving means to retrieve said samples from said memory; (c) estimate a number of said retrieved samples that constitutes a pitch period of said signals; (d) cause said reproducing means to reproduce a group of said retrieved samples, said group consisting of a number of samples, said number being equal to said estimated number; (e) after step (d), combine a first group of said retrieved samples with a second group of said retrieved samples to form a combined group, said first group and second group each consisting of a same number of sequential samples, said same number being equal to said estimated number, said second group immediately following said first group in said sequence of samples; and (f) cause said reproducing means to reproduce said combiend group.