CALLFRIEND Mandarin Chinese-Mainland Dialect Second Edition

Item Name: CALLFRIEND Mandarin Chinese-Mainland Dialect Second Edition
Author(s): Alexandra Canavan, George Zipperlen, John Bartlett
LDC Catalog No.: LDC2018S09
ISBN: 1-58563-851-X
ISLRN: 466-791-939-707-1
Release Date: July 16, 2018
Member Year(s): 2018
DCMI Type(s): Sound
Sample Type: ulaw
Sample Rate: 8000
Data Source(s): telephone conversations
Project(s): EARS, GALE, LID
Application(s): language identification
Language(s): Mandarin Chinese
Language ID(s): cmn
License(s): LDC User Agreement for Non-Members
Online Documentation: LDC2018S09 Documents
Licensing Instructions: Subscription & Standard Members, and Non-Members
Citation: Canavan, Alexandra, George Zipperlen, and John Bartlett. CALLFRIEND Mandarin Chinese-Mainland Dialect Second Edition LDC2018S09. Web Download. Philadelphia: Linguistic Data Consortium, 2018.
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CALLFRIEND Mandarin Chinese-Mainland Dialect Second Edition was developed by the Linguistic Data Consortium (LDC) and consists of approximately 24 hours of unscripted telephone conversations between native speakers of the Mandarin Chinese dialect spoken in mainland China. This second edition updates the audio files to wav format, simplifies the directory structure and adds documentation and metadata. The first edition is available as CALLFRIEND Mandarin Chinese-Mainland Dialect (LDC96S55).

The CALLFRIEND series is a collection of telephone conversations in several languages conducted by LDC in support of language identification technology development. Languages covered in the collection include American English, Canadian French, Egyptian Arabic, Farsi, German, Hindi, Japanese, Korean, Mandarin Chinese, Spanish, Tamil and Vietnamese.


All data was collected before July 1997. Participants could speak with a person of their choice on any topic; most called family members and friends. All calls originated in North America. The recorded conversations last up to 30 minutes.

The data was recorded as 8kHz u-law SPH encoded stereo files, with one end of the phone call on each channel. In this release, files were converted to WAV format, and information from the original SPH headers is described in the documentation. SPH files are not included in this second edition.

The audio files were originally split into train, dev and test folders of 20 recordings each, but they are combined in this release.

Completed calls passed through two human audits. The first audit was conducted to verify that the target language was spoken by the participants and to check the quality of the recordings. The second audit was conducted by a native speaker familiar with Mainland and Taiwanese Mandarin dialects to classify the conversations under one of the two categories.


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