Fisher English Training Speech Part 1 Speech

Item Name: Fisher English Training Speech Part 1 Speech
Author(s): Christopher Cieri, David Graff, Owen Kimball, Dave Miller, Kevin Walker
LDC Catalog No.: LDC2004S13
ISBN: 1-58563-313-5
ISLRN: 259-501-047-379-0
Release Date: December 15, 2004
Member Year(s): 2004
DCMI Type(s): Sound
Sample Type: ulaw
Sample Rate: 8000
Data Source(s): telephone conversations
Project(s): EARS, GALE
Application(s): speech recognition
Language(s): English
Language ID(s): eng
License(s): LDC User Agreement for Non-Members
Online Documentation: LDC2004S13 Documents
Licensing Instructions: Subscription & Standard Members, and Non-Members
Citation: Cieri, Christopher, et al. Fisher English Training Speech Part 1 Speech LDC2004S13. Web Download. Philadelphia: Linguistic Data Consortium, 2004.
Related Works: View


Fisher English Training Speech Part 1 Speech was developed by the Linguistic Data Consortium (LDC) and contains 984 hours of English conversational telephone speech (CTS). The corresponding transcripts for these speech files are available in Fisher English Training Speech Part 1, Transcripts (LDC2004T19).

These two corpora represent the first half of a conversational telephone speech (CTS) collection that was created at LDC during 2003. The second half of the collection, released in 2005, comprises Fisher English Training Part 2, Transcripts (LDC2005T19) and Fisher English Training Part 2, Speech (LDC2005S13). Taken as a whole, the two parts contain 11,699 recorded telephone conversations totaling approximately 1,960 hours.

The Fisher telephone conversation collection protocol was created at LDC to address a critical need of developers trying to build robust automatic speech recognition (ASR) systems. Previous collection protocols, such as CALLFRIEND and Switchboard-II and the resulting corpora, have been adapted for ASR research but were in fact developed for language and speaker identification, respectively. Although the CALLHOME protocol and corpora were developed to support ASR technology, they feature small numbers of speakers making telephone calls of relatively long duration with narrow vocabulary across the collection. CALLHOME conversations are challengingly natural and intimate. Under the Fisher protocol, a large number of participants are allowed to make up to three 10 minute calls. For each call, a participant is paired with another participant, whom they typically do not know, to discuss assigned topics. This maximizes inter-speaker variation and vocabulary breath while also increasing formality.

Previous protocols such as CALLHOME, CALLFRIEND, and Switchboard relied upon participant activity to drive the collection. Fisher is unique in being platform-driven rather than participant-driven. Participants who wish to initiate a call may do so, however, the collection platform initiates the majority of calls. Participants need only answer their phones at the times they specified when registering for the study.

To encourage a broad range of vocabulary, Fisher participants are asked to speak about an assigned topic chosen from a randomly generated list that changes every 24 hours. All participants that day will be assigned subjects from that list. Some topics are inherited or refined from previous Switchboard studies while others were developed specifically for the Fisher protocol.


This corpus contains 5,850 audio files, each one containing a full conversation of up to 10 minutes. Additional information regarding the speakers involved and types of telephones used can be found in the companion text corpus of transcripts listed above. The individual audio files are presented in NIST SPHERE format and contain two-channel mu-law sample data. Shorten compression has been applied to all files.

For the entire collection, here is the gender breakdown for the participants: 6,813 female, 5,104 male.

Data collection and transcription were sponsored by DARPA and the U.S. Department of Defense, as part of the EARS project for research and development in ASR.


Please examine this sample to see an example of the data in this corpus.

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