Multi-Language Conversational Telephone Speech 2011 -- Central European

Item Name: Multi-Language Conversational Telephone Speech 2011 -- Central European
Author(s): Karen Jones, David Graff, Kevin Walker, Stephanie Strassel
LDC Catalog No.: LDC2018S08
ISBN: 1-58563-850-1
ISLRN: 023-068-508-797-0
Release Date: June 15, 2018
Member Year(s): 2018
DCMI Type(s): Sound
Sample Type: pcm
Sample Rate: 8000
Data Source(s): telephone conversations
Project(s): NIST LRE
Application(s): language identification
Language(s): Czech, Slovak
Language ID(s): ces, slk
License(s): LDC User Agreement for Non-Members
Online Documentation: LDC2018S08 Documents
Licensing Instructions: Subscription & Standard Members, and Non-Members
Citation: Jones, Karen, et al. Multi-Language Conversational Telephone Speech 2011 -- Central European LDC2018S08. Web Download. Philadelphia: Linguistic Data Consortium, 2018.
Related Works: View


Multi-Language Conversational Telephone Speech 2011 -- Central European was developed by the Linguistic Data Consortium (LDC) and is comprised of approximately 44 hours of telephone speech in two distinct language varieties of Central Europe: Czech and Slovak.

The data were collected primarily to support research and technology evaluation in automatic language identification, and portions of these telephone calls were used in the NIST 2011 Language Recognition Evaluation (LRE). LRE 2011 focused on language pair discrimination for 24 languages/dialects, some of which could be considered mutually intelligible or closely related.

LDC has also released the following as part of the Multi-Language Conversational Telephone Speech 2011 series:


Participants were recruited by native speakers who contacted acquaintances in their social network. Those native speakers made one call, up to 15 minutes, to each acquaintance. The data was collected using LDC's telephone collection infrastructure, comprised of three computer telephony systems. Human auditors labeled calls for callee gender, dialect type and noise. Demographic information about the participants was not collected.

All audio data are presented in FLAC-compressed MS-WAV (RIFF) file format (*.flac); when uncompressed, each file is 2 channels, recorded at 8000 samples/second with samples stored as 16-bit signed integers, representing a lossless conversion from the original mu-law sample data as captured digitally from the public telephone network. The following table summarizes the total number of calls, total number of hours of recorded audio, and the total size of compressed data:

group lng #calls #hours #MB
c_europ ces 92 21.9 1076
c_europ slk 93 22.6 1104
c_europ Totals 185 44.5 2180


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