NIST 2005 Speaker Recognition Evaluation Test Data, Linguistic Data Consortium
(LDC) catalog number LDC2011S04 and isbn 1-58563-586-3, was developed at LDC
and NIST (National Institute of Standards and Technology). It consists of 525 hours of conversational telephone speech in English, Arabic, Mandarin Chinese, Russian and Spanish and associated English transcripts used as test data in the NIST-sponsored 2005
Speaker Recognition Evaluation (SRE). The ongoing series of SRE yearly evaluations
conducted by NIST are intended to be of interest to researchers working on the
general problem of text independent speaker recognition. To that end the evaluations
are designed to be simple, to focus on core technology issues, to be fully supported
The task of the 2005 SRE evaluation was speaker detection, that is, to determine
whether a specified speaker is speaking during a given segment of conversational
speech. The task was divided into 20 distinct and separate tests involving
one of five training conditions and one of four test conditions. Further information
about the task conditions is contained in the The NIST Year 2005 Speaker Recognition
The training data for the 2005 evaluation is available in NIST 2005 Speaker Recognition Evaluation Training Data LDC2011S01.
The speech data consists of conversational telephone speech with multi-channel
data collected by LDC simultaneously from a number of auxiliary microphones. The files
are organized into two segments: 10 second two-channel excerpts (continuous
segments from single conversations that are estimated to contain approximately
10 seconds of actual speech in the channel of interest) and 5 minute two-channel
The data are stored as 8-bit u-law speech signals in NIST SPHERE
format. In addition to the standard header fields, the SPHERE header for each
file contains some auxiliary information that includes the language of the conversation
and whether the data was recorded over a telephone line.
English language word transcripts in .cmt format were produced using an automatic
speech recognition system (ASR) with error rates in the range of 15-30%.
For an example of the data contained in this corpus, review this audio sample.
Trials files for the 2005 SRE were added Jan. 05, 2012 in the LDC2011S04U01 update. These files defines the various evaluation tests, one file for each trial in the evaluation. The index.html and file.tbl files were also updated. All new copies of this corpora ordered after this date should come already updated. Please contact firstname.lastname@example.org with any questions.
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