184 results about "Monaural" patented technology

The present technology provides a robust noise suppression system that may concurrently reduce noise and echo components in an acoustic signal while limiting the level of speech distortion. An acoustic signal may be received and transformed to cochlear domain sub-band signals. Features, such as pitch, may be identified and tracked within the sub-band signals. Initial speech and noise models may be then be estimated at least in part from a probability analysis based on the tracked pitch sources. Speech and noise models may be resolved from the initial speech and noise models and noise reduction may be performed on the sub-band signals. An acoustic signal may be reconstructed from the noise-reduced sub-band signals.

Systems and methods are disclosed for packet voice conferencing. An encoding system accepts two sound field signals, representing the same sound field sampled at two spatially-separated points. The relative delay between the two sound field signals is detected over a given time interval. The sound field signals are combined and then encoded as a single audio signal, e.g., by a method suitable for monophonic VoIP. The encoded audio payload and the relative delay are placed in one or more packets and sent to a decoding device via the packet network. The decoding device uses the relative delay to drive a playout splitter-once the encoded audio payload has been decoded, the playout splitter creates multiple presentation channels by inserting the transmitted relative delay in the decoded signal for one (or more) of the presentation channels. The listener thus perceives a speaker's voice as originating from a location related to the speaker's physical position at the other end of the conference. An advantage of these embodiments is that a pseudo-stereo conference can be conducted with virtually the same bandwidth as a monophonic conference.

A stereo headphone employing a standard stereo headphone plug is adapted for automatically hearing a monaural signal at both earpieces, when accessing a typical monaural source. In the first embodiment of the invention, an impedance element couples the signal from a first acoustical driver that receives the monaural signal from the stereo plug tip, to a second acoustical driver that is connected to the stereo plug ring and normally receives no signal when plugged into a conventional monaural audio source output jack. The magnitude of the coupling impedance is selected with respect to the impedance of the acoustical driver so that the reduction in loudness at the second earpiece due to the signal voltage drop across the coupling impedance is not perceptible to the listener. This will occur when the reduction in loudness at the second earpiece is less than the threshold of perceivable loudness reduction at one ear when there is no reduction in loudness at the other ear. The effect of the coupling impedance, when listening to a stereo audio source is insignificant, firstly, because the two stereo channel signals appear at their respective drivers with virtually no attenuation due to the coupling impedance. Secondly, although the coupling impedance does contribute a slight amount of additional crosstalk between the stereo channels, the magnitude of the increase in crosstalk is dependent upon the ratio of the coupling impedance to the output impedance of the stereo source. A typical stereo source for which the use of this headphone is intended has an output impedance so low compared to the coupling impedance that the increase in crosstalk is too small to be perceptible as affecting the stereo separation or the stereo imaging afforded by the stereo source. In the second embodiment of the invention two equal impedance elements couple the monaural signal from the stereo plug tip to each acoustical driver. This equalizes the loudness of the monaural signal heard at each earpiece and slightly reduces the level of one stereo channel with respect to the other. Crosstalk and stereo imaging are virtually unaffected, as with the first embodiment.

A method and apparatus are disclosed for providing a virtual auditorium for a remote, live performance to a remote, distributed audience, wherein the performers receive the reaction of the audience members in substantially real time. The live performance can itself be distributed geographically, as taught in the prior art, and may be multimedia in nature, for example audio (monophonic, stereo, or multi-channel) can be augmented by images, video, MIDI, text (e.g., commentary, lyrics), etc. Further, the distributed audience members can receive each other's reaction, also in substantially real time, whereby the virtual auditorium is created wherein the distributed audience members constitute a virtual assembly.The same virtual auditorium, sans performers, can be used as a venue to conduct a conference call of arbitrary size without the expense of a central voice bridge.