Abstract: A method for a machine or group of machines to carry watermark data in an encoded audio data frame of an audio signal includes receiving the encoded audio data frame having encoded therein a portion of the audio signal. The encoded audio data frame includes a plurality of data blocks, wherein the plurality of data blocks includes, a synchronization information block, at least one encoded data block, and an error check block. The method further includes receiving modified watermark data as modified based on a masking threshold analysis of the audio signal and transforming the encoded audio data frame into a modified encoded audio data frame.

Abstract: Providing feedback regarding potential detectability by a decoder of a watermark message produced by a watermarking encoder includes receiving a watermark detectability indication that does not directly correspond to detectability of the watermark message by the decoder but is only a proxy for detectability of the watermark message by the decoder, transforming the watermark detectability indication into an enhancement indication corresponding to a prescribed enhancement to a watermark signal in which the watermark message is embedded based on the watermark detectability indication, and transmitting the enhancement indication to enhance the watermark signal thereby enhancing detectability of the watermark message.

Abstract: Optimizing parameters includes, during a time interval, rotating from setting a first parameter to a first value for a first time period, to setting the first parameter to a second value for a second time period such that the time interval includes multiple first time periods in which the first parameter is set to the first value sequenced with multiple second time periods in which the first parameter is set to the second value; obtaining, for the time interval, a first set of ratings corresponding to the first time periods and a second set of ratings corresponding to the second time periods; averaging, for the time interval, the first set of ratings to a first average rating and the second set of ratings to a second average rating; and correlating the first average rating to the first value and the second average rating to the second value.

Abstract: Providing feedback regarding potential detectability by a decoder of a watermark message produced by a watermarking encoder includes receiving a watermark detectability indication that does not directly correspond to detectability of the watermark message by the decoder but is only a proxy for detectability of the watermark message by the decoder, transforming the watermark detectability indication into an enhancement indication corresponding to a prescribed enhancement to a watermark signal in which the watermark message is embedded based on the watermark detectability indication, and transmitting the enhancement indication to enhance the watermark signal thereby enhancing detectability of the watermark message.

Abstract: A system for providing feedback regarding detectability of a watermark message produced by a watermarking encoder includes a simulation module configured to combine at least one of a watermarked signal or an enhanced watermarked signal with a simulated environment signal that corresponds to an expected listening environment of the at least one of the watermarked signal or the enhanced watermarked signal, and output a simulated environment-modified watermarked signal corresponding to the combination of the at least one of the watermarked signal or the enhanced watermarked signal with the simulated environment signal, and a monitoring module configured to generate a watermark detectability indication based on the simulated environment-modified watermarked signal.

Abstract: Providing feedback regarding detectability of a watermark message produced by a watermarking encoder may include receiving a watermark detectability indication corresponding to detectability of the watermark message, and determining an enhancement indication corresponding to a prescribed enhancement to a watermark signal in which the watermark message is embedded based on the watermark detectability indication.

Abstract: A device for enhancing a watermark signal extracted from an output signal of a watermarking encoder including an input signal portion corresponding to an input signal to the watermarking encoder and a watermark signal portion corresponding to the watermark signal includes an input configured to receive the input signal and the watermark signal, an enhancement module operatively connected to the input and configured to a) enhance the watermark signal at least in part by adjusting a gain of the watermark signal to obtain an enhanced watermark signal, and b) generate an enhanced output signal including an input signal portion corresponding to the input signal and an enhanced watermark signal portion corresponding to the enhanced watermark signal.

Abstract: A device for extracting a watermark signal from an output signal of a watermarking encoder in which the output signal includes an input signal portion corresponding to an input signal to the watermarking encoder and a watermark signal portion corresponding to the watermark signal includes an input configured to receive the input signal and the output signal. The device further includes an adjustment signal generator configured to generate a gain adjustment signal and a delay adjustment signal based on the input signal and the output signal, a gain and delay adjustor configured to adjust gain and delay of the output signal or the input signal based on the gain adjustment signal and the delay adjustment signal, respectively, to generate an adjusted output signal or an adjusted input signal, respectively, and an output configured to transmit a difference between the input signal and the adjusted output signal or a difference between the adjusted input signal and the output signal as the watermark signal.

Abstract: A system for monitoring detectability of a watermark message produced by a watermarking encoder includes an input that receives a watermarked signal having spectral channels in which the watermark message is embedded. The system also includes channel separators each associated with a respective spectral channel of the watermarked signal and configured to separate the watermarked signal into spectral channels. The system also includes bin separators configured to separate the spectral channels into frequency bins. The system also includes a detector configured to detect a frequency bin corresponding to a symbol that appears in a plurality of the spectral channels. The system also includes a detectability estimator configured to establish a measure of the detectability of the watermark message embedded in the watermarked signal based at least in part on the frequency bin corresponding to the symbol that appears in the plurality of the spectral channels.

Abstract: An apparatus and method simulates more accurately the natural statistics of a physical reverberation process. A new filter design is provided having a comb shaped group delay. Gain minimums at a plurality of frequencies are combined with a delay line to create a constant reverberation time independent of frequency while allowing for temporal spreading. In addition, the connection topology between the plurality of energy transmission networks is temporally randomized to facilitate energy distribution within the reverberation apparatus. Both the temporal and spectral responses are actively changed on each iteration of the energy recirculation. By making the response have a high echo density and a lack of spectral coloration in the decay, the illusion of a natural process is enhanced.

Abstract: An apparatus and method simulates more accurately the natural statistics of a physical reverberation process. A new filter design is provided having a comb shaped group delay. Gain minimums at a plurality of frequencies are combined with a delay line to create a constant reverberation time independent of frequency while allowing for temporal spreading. In addition, the connection topology between the plurality of energy transmission networks is temporally randomized to facilitate energy distribution within the reverberation apparatus. Both the temporal and spectral responses are actively changed on each iteration of the energy recirculation. By making the response have a high echo density and a lack of spectral coloration in the decay, the illusion of a natural process is enhanced.

Abstract: An apparatus and method simulates more accurately the natural statistics of a physical reverberation process. A new filter design is provided having a comb shaped group delay. Gain minimums at a plurality of frequencies are combined with a delay line to create a constant reverberation time independent of frequency while allowing for temporal spreading. In addition, the connection topology between the plurality of energy transmission networks is temporally randomized to facilitate energy distribution within the reverberation apparatus. Both the temporal and spectral responses are actively changed on each iteration of the energy recirculation. By making the response have a high echo density and a lack of spectral coloration in the decay, the illusion of a natural process is enhanced.

Abstract: An apparatus and method simulates more accurately the natural statistics of a physical reverberation process. A new filter design is provided having a comb shaped group delay. Gain minimums at a plurality of frequencies are combined with a delay line to create a constant reverberation time independent of frequency while allowing for temporal spreading. In addition, the connection topology between the plurality of energy transmission networks is temporally randomized to facilitate energy distribution within the reverberation apparatus. Both the temporal and spectral responses are actively changed on each iteration of the energy recirculation. By making the response have a high echo density and a lack of spectral coloration in the decay, the illusion of a natural process is enhanced.

Abstract: An apparatus and method simulates more accurately the natural statistics of a physical reverberation process. A new filter design is provided having a comb shaped group delay. Gain minimums at a plurality of frequencies are combined with a delay line to create a constant reverberation time independent of frequency while allowing for temporal spreading. In addition, the connection topology between the plurality of energy transmission networks is temporally randomized to facilitate energy distribution within the reverberation apparatus. Both the temporal and spectral responses are actively changed on each iteration of the energy recirculation. By making the response have a high echo density and a lack of spectral coloration in the decay, the illusion of a natural process is enhanced.

Abstract: An apparatus and method simulates more accurately the natural statistics of a physical reverberation process. A new filter design is provided having a comb shaped group delay. Gain minimums at a plurality of frequencies are combined with a delay line to create a constant reverberation time independent of frequency while allowing for temporal spreading. In addition, the connection topology between the plurality of energy transmission networks is temporally randomized to facilitate energy distribution within the reverberation apparatus. Both the temporal and spectral responses are actively changed on each iteration of the energy recirculation. By making the response have a high echo density and a lack of spectral coloration in the decay, the illusion of a natural process is enhanced.

Abstract: A digitizing tablet is disclosed in which two sets of circuitous conductive lines form grids each connected at one end to a surrounding conductive loop. All outputs are measured from the conductive loop as a multiplexor sequentially grounds the grids one at a time. The outputs are fed through linear spatial filters which are used to produce intermediate signals which are in turn combined to arrive at raw position signals for a position indicating coil located over the work surface. Separate sets of linear spatial filters may be used to produce two raw position signals differently responsive to tilt which can then be combined to arrive at a true position signal insensitive to tilt.

Abstract: A digitizing tablet system having a stylus which is inductively coupled to a grid is disclosed. The grid includes a first plurality of narrow uniformly sized and spaced U shaped loops of conductive material disposed to define a first coordinate axis of the grid and a second plurality of narrow uniformly sized and spaced U shaped loops of conductive material disposed to define a second coordinate axis of the grid. One end point of each loop in each plurality of loops is connected to a common conductor which serves as one output terminal for that plurality of loops. The other end point of each loop in the same plurality of loops is connected to a multiplexor whose output is connected to a conductor which serves as the other output terminal for that plurality of loops. Voltage signals induced in the loops when the stylus is positioned above the grid and a coil in the stylus is energized are processed to generate data signals corresponding to the position of the stylus relative to the grid structure.

Abstract: A digital data communications system transmits digital data over a telephone line using frequency multiplexing for the different channels. Each channel includes a receiver and a transmitter coupled to the telephone line at spaced points. Each transmitter includes an FSK modulator, a bandpass filter of controllable bandwidth centered about 5 kHz with its bandwidth controlled by a bandwidth select signal related to the bandwidth needed to transmit data over that channel. A mixer combines the output of the bandpass filter with a local oscillator signal of frequency related to the selected channel to provide a difference frequency signal that is applied to a lowpass filter having a cutoff at 3 kHz that is coupled to the telephone line. Each receiver includes a lowpass filter having a cutoff at 3 kHz that couples the line to a mixer.

Abstract: A digitizing tablet is disclosed in which two multiplexors are connected to alternate conductive loop elements in each plane of elements. The two multiplexors are connected to a differential amplifier. The signals from the differential amplifier are demodulated. The demodulated signal is provided to an integrator. A microprocessor controlled reset switch is connected across the integrator to reset the integrator after the completion of each measurement. Grounded copper strips are used in the space formed within and between the conductive loop elements of the digitizing tablet to shield the loop elements from capacitive interference.

Abstract: A position indicating implement is disclosed having a first coil connected to a current source and a second coil inductively coupled with the first coil. A capacitor is connected in series with the second coil so that the current in the first coil induces a phase shifted current in the second coil. A tip extends from the barrel of the position indicating implement of the present invention. The tip is designed for placement on and movement over a digitizing tablet. A switch has been located near the tip so that it is easily accessible to a user's finger while holding the implement.The power source providing an alternating current to the first coil includes a digital switching circuit for producing a step function which approximates a sine wave and lacks any components at the second, third, fourth, fifth and sixth harmonics. The step function is filtered to produce a sine wave for delivery to the first coil.