SYSTEMS AND METHODS FOR REDUCING SPEECH INTELLIGIBILITY WHILE PRESERVING ENVIRONMENTAL SOUNDS
First Claim
1. A method for reducing speech intelligibility while preserving environmental sounds, the method comprising:
- receiving an audio signal;
processing the audio signal to separate a vocalic region;
computing a representation of at least the vocalic region, the representation including at least a vocal tract transfer function and an excitation;
replacing the vocal tract transfer function of the vocalic region with a replacement sound transfer function of a replacement sound to create a modified vocal tract transfer function; and
synthesizing a modified audio signal of at least the vocalic region from the modified vocal tract transfer function and the excitation.
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Accused Products
Abstract
An audio privacy system reduces the intelligibility of speech in an audio signal while preserving prosodic information, such as pitch, relative energy and intonation so that a listener has the ability to recognize environmental sounds but not the speech itself. An audio signal is processed to separate non-vocalic information, such as pitch and relative energy of speech, from vocalic regions, after which syllables are identified within the vocalic regions. Representations of the vocalic regions are computed to produce a vocal tract transfer function and an excitation. The vocal tract transfer function for each syllable is then replaced with the vocal tract transfer function from another prerecorded vocalic sound. In one aspect, the identity of the replacement vocalic sound is independent of the identity of the syllable being replaced. A modified audio signal is then synthesized with the original prosodic information and the modified vocal tract transfer function to produce unintelligible speech that preserves the pitch and energy of the speech as well as environmental sounds.
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Citations
34 Claims
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1. A method for reducing speech intelligibility while preserving environmental sounds, the method comprising:
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receiving an audio signal; processing the audio signal to separate a vocalic region; computing a representation of at least the vocalic region, the representation including at least a vocal tract transfer function and an excitation; replacing the vocal tract transfer function of the vocalic region with a replacement sound transfer function of a replacement sound to create a modified vocal tract transfer function; and synthesizing a modified audio signal of at least the vocalic region from the modified vocal tract transfer function and the excitation. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A system for reducing speech intelligibility while preserving environmental sounds, the system comprising:
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a receiving module for receiving an audio signal; a voicing detector for processing the audio signal to separate a vocalic region; a computation module for computing a representation of at least the vocalic regions, the representation including at least a vocal tract transfer function and an excitation; a replacement module for replacing the vocal tract transfer function of the vocalic region with a replacement vocal tract transfer function of a replacement sound to create a modified vocal tract transfer function; and an audio synthesizer for synthesizing a modified audio signal of at least the vocalic region from the modified vocal tract transfer function and the excitation. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34)
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Specification