Speech recognition apparatus

Claim 2

Apparatus as set forth in claim 2 wherein said delay means provides in the order of ten differently delayed signals from said given signal.

Claim 3

Apparatus as set forth in claim 3 wherein the delays provided by said delay means differ over a range of about one millisecond.

Claim 4

Apparatus as set forth in claim 4 wherein said output signal generating means include a detector circuit to which said composite signal is applied.

Claim 5

Apparatus as set forth in claim 1 wherein each of said weighting means includes means for selectively reversing the phase of the respective delayed signal contribution to the composite signal.

Claim 6

Apparatus for determining whether a given analog signal corresponds to a preselected vocal sound, said apparatus comprising: means for compensating proportionally for variations in the average amplitude of said given signal from a substantially predetermined average amplitude; delay means providing a plurality of differently delayed signals from said signal of predetermined amplitude; a corresponding plurality of means for respectively weighting said differently delayed signals in selected phase polarity; means for linearly mixing said delayed and weighted signals thereby to obtain a composite signal, the contribution from each delayed signal being weighted as a respective function of a corresponding characteristic of the preselected vocal sound; and means for generating an output signal when the average amplitude of said composite signal crosses a selected threshold thereby to indicate that the given signal corresponds to said preselected vocal sound.

Claim 7

Apparatus for identifying which of a plurality of preselected vocal sounds is represented by a given analog signal, said apparatus comprising: delay means providing a plurality of differently delayed signals corresponding to said given signal; for each of said preselected vocal sounds, a respective plurality of means for respectively weighting said differently delayed signals; for each of said preselected vocal sounds, a respective means for linearly mixing the respective set of delayed and weighted signals thereby to obtain a respective function composite signal, the contribution from each delayed signal being weighted as a respective function of a corresponding characteristic of the respective vocal sound; and means for indicating which of said composite signals has an average amplitude which is in a preselected relationship to the average amplitudes of the other composite signals thereby to identify which of the corresponding vocal sounds is best represented by said given signal.

Claim 8

Apparatus as set forth in claim 8 wherein each of said weighting means includes means for selectively reversing the phase of the signal contribution to the respective composite signals.

Claim 9

Apparatus as set forth in claim 8 wherein said apparatus includes an a.g.c. amplifier for bringing an input signal of varying amplitude to a predetermined average amplitude.

Claim 10

Apparatus as set forth in claim 8 wherein said comparator circuit provides a signal indicating which of said composite signals has the smallest average amplitude.

Claim 11

Apparatus for identifying which of a plurality of preselected vocal sounds corresponds most closely to a given analog voice signal, said apparatus comprising: a delay line having a plurality of taps providing different delays; means for applying said given analog voice signal to said delay line; for each of said vocal sounds, a respective means for respectively weighting said differently delayed signals; for each of said vocal sounds, a respective mixing network for linearly summing the respective set of delayed and weighted signal components taken from said different taps thereby to obtain a respective composite signal, each network including means for weighting the contribution from each tap as a respective function of a corresponding characteristic of the respective vocal sound; a detector circuit for each mixing network providing a signal voltage which varies as a function of the average amplitude of the respective composite signal; and a comparator circuit responsive to said signal voltages for providing a signal indicating which of said composite signals has the smallest amplitude thereby to indicate that the respective vocal sound is the one which corresponds most closely to said given voice signal.

Claim 12

Apparatus as set forth in claim 12 including means for inhibiting the operation of said comparator circuit when the amplitude of said given signal falls below a preselected level.