Switchboard-2 Phase II

Item Name: Switchboard-2 Phase II
Author(s): David Graff, Kevin Walker, Alexandra Canavan
LDC Catalog No.: LDC99S79
ISBN: 1-58563-144-2
ISLRN: 777-596-800-424-2
DOI: https://doi.org/10.35111/5qpg-1r82
Member Year(s): 1999
DCMI Type(s): Sound
Sample Type: 2-channel ulaw
Sample Rate: 8000
Data Source(s): telephone conversations
Application(s): speaker identification
Language(s): English
Language ID(s): eng
License(s): LDC User Agreement for Non-Members
Online Documentation: LDC99S79 Documents
Licensing Instructions: Subscription & Standard Members, and Non-Members
Citation: Graff, David, Kevin Walker, and Alexandra Canavan. Switchboard-2 Phase II LDC99S79. Web Download. Philadelphia: Linguistic Data Consortium, 1999.
Related Works: View


Switchboard-2 Phase II consists of 4,472 five-minute telephone conversations involving 679 participants. This corpus was collected by the Linguistic Data Consortium (LDC) in support of a project on Speaker Recognition sponsored by the U.S. Department of Defense.


Participants in SWB-2 Phase II were recruited from the following midwestern college campuses: Iowa State University, Michigan State University, University of Michigan, University of Minnesota, University of Wisconsin at Madison, Northwestern University, and Ohio State University. Solicitation methods included the Internet, newspaper advertisements and personal contacts. The majority of the participants resided in Minnesota, Wisconsin, Ohio, Iowa, Michigan and Illinois as follows:

Minnesota - 156 speakers

Wisconsin -- 105 speakers

Ohio -- 70 speakers

Iowa 64 speakers

Michigan -- 41 speakers

Illinois - 37 speakers

Each recruit was asked to participate in at least ten five-minute phone calls. Ideally each participant would receive five calls at a designated number and make five calls from phones with different (ANI) codes. Participants were asked to discuss a specific topic (read by the automated operator) and not to provide personal information during their call.

Each of the 679 participants placed their calls via a toll-free robot operator maintained by LDC. Access to the robot operator was possible via a unique Personal Identification Number (PIN) issued by the recruiting staff at LDC when the caller enrolled in the project.

Upon conclusion of the study all calls were audited by LDC staff members. Particular attention was paid to PIN verification (matching speaker with PIN), checking call duration, and call quality. Upon completion of this process, checks were issued and mailed to participants. The conversations have not been transcribed.


09/10/2021: callinfo.tbl and callstat.tbl were found to have errors and were replaced.

09/29/2011: The file table and readme were updated to reflect that this data set was made available on DVD.

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