Fisher Spanish - Speech was developed by LDC and
consists of audio files covering roughly 163 hours of telephone
speech from 136 native Caribbean Spanish and non-Caribbean Spanish
speakers. Full orthographic transcripts of these audio files are
available in Fisher
Spanish - Transcripts (LDC2010T04).
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 very large
number of participants each make a few calls of short duration speaking to other
participants, whom they typically do not know, about assigned topics. This maximizes
inter-speaker variation and vocabulary breadth although it also increases 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 on an assigned topic which is selected at random from a
list, which changes every 24 hours and which is assigned to all
subjects paired on that day. Some topics are inherited or refined from
previous Switchboard studies while others were developed specifically
for the Fisher protocol.
In collecting data for this corpus, attempts were made to provide a
representative distribution of subjects across a variety of
demographic categories including: gender, age, dialect region, and
This corpus joins other Fisher corpora: Arabic CTS Levantine
Fisher Training Data Set 3 (LDC2005S07,
Fisher English Training Part 2 (LDC2005S13,
Fisher English Training Speech Part 1 (LDC2004S13,
and Fisher Levantine Arabic Conversational Telephone Speech (LDC2007S02,
The speech recordings consist of 819 telephone conversations of 10 to 12 minutes
in duration. They are provided as digital audio files in NIST SPHERE format
(1024-byte ASCII file headers). The conversations were recorded as 2-channel
mu-law sample data with 8000 samples per second (as captured from the public
The accompanying transcript files (availabel in Fisher
Spanish - Transcripts (LDC2010T04)) are in plain-text, tab-delimited format (tdf) with UTF-8
character encoding. They were created with the LDC-developed transcription tool
allowed for improved handling of multi-channel audio and overlapping speakers.
XTrans is available from LDC.
Guidelines (NQTR), which are included with the documentation
for this release.
The first line of each transcript file provides the column headings; the next
two lines are "comments" that can be ignored (these are used by XTrans; they
are distinguished from non-comment lines by having an initial semicolon ";").
Actual transcript data, with time stamps, channel number, transcript text and
additional information, begins at line 4 of each transcript file.
Native speakers of Caribbean Spanish and non-Caribbean Spanish were
recruited from within the continental United States and Puerto
Rico. The following tables provide an overview of the demographics
of the participants. The Subjects Table file, provided in the
documentation, may be used to answer questions about specific
combinations of participant characteristics (including level of
Please examine this excerpt (converted to wav format for simpler online distribution) for an example of the data in this corpus.
Portions © 2005-2006, 2010 Trustees of the University of Pennsylvania