22. A non-transitory computer-readable storage medium comprising instructions for causing one or more processor to: receive a spoken utterance; generate a first phoneme-independent representation based on the spoken utterance; decompose the first phoneme-independent representation into at least one content-independent characteristic unit; compare the at least one content-independent characteristic unit to at least one-content-independent recognition distribution value associated with a registered user of a device, the at least one content-independent recognition distribution value previously generated by: generate a second phoneme-independent representation based on speech from the registered user; and decompose the second phoneme-independent representation into a content-independent recognition unit, the at least one content-independent recognition distribution value based on the content-independent recognition unit; and determine that the spoken utterance is spoken by the registered user if the at least one content-independent characteristic unit is within a threshold limit of the at least one content-independent recognition distribution value.
22. A non-transitory computer-readable storage medium comprising instructions for causing one or more processor to: receive a spoken utterance; generate a first phoneme-independent representation based on the spoken utterance; decompose the first phoneme-independent representation into at least one content-independent characteristic unit; compare the at least one content-independent characteristic unit to at least one-content-independent recognition distribution value associated with a registered user of a device, the at least one content-independent recognition distribution value previously generated by: generate a second phoneme-independent representation based on speech from the registered user; and decompose the second phoneme-independent representation into a content-independent recognition unit, the at least one content-independent recognition distribution value based on the content-independent recognition unit; and determine that the spoken utterance is spoken by the registered user if the at least one content-independent characteristic unit is within a threshold limit of the at least one content-independent recognition distribution value. 23. The computer-readable storage medium of claim 22 , further comprising instructions for causing the one or more processor to: generate the at least one content-independent characteristic unit from a singular value matrix of a singular value decomposition of the first phoneme-independent representation.