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
Member Year(s): 1999
DCMI Type(s): Sound
Sample Type: 2-channel ulaw
Sample Rate: 8000
Data Source(s): telephone conversations
Project(s): SID, GALE, EARS
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.


SWB-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.


Speakers were solicited by the LDC to participate in this telephone speech collection effort via the Internet, newspaper advertisements, and personal contacts. The majority of participants resided in the following states:

State Number of Speakers -------------------------- MN 156 WI 105 OH 70 IA 64 MI 41 IL 37

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.

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 the LDC. Access to the robot operator was possible via a unique Personal Identification Number (PIN) issued by the recruiting staff at the 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.


09/29/2011: Updated the file table to accurately reflect the files now that they are on DVDs. Also, updated the readme to indicate these changes.

Available Media

View Fees

Extra Copy
Login for the applicable fee