Switchboard Cellular Part 1 Audio


The Switchboard Cellular Phase 1 Audio produced by the Linguistic Data Consortium, catalog number LDC2001S13 and isbn number 1-58563-213-9. This release contains speech data files ONLY, along with documentation describing speaker information (sex, age, education, city and state where raised), call information (date, time, call duration, Personal Identification Numbers, topic), and audit information (channel quality, background noise). The data files are not compressed.

The Switchboard Cellular Part 1 collection focused primarily on GSM cellular phone technology. The collection commenced 11/12/1999 and was completed on 05/15/2000. The project's goal was to target 190 subjects, balanced by gender, under varied environmental conditions to participate in (10+) 5-6 minute conversations on GSM cellular phones. The speech data was collected for research, development, and evaluation of automatic systems for speech-to-text conversion, talker identification, language identification and speech signal detection purposes.

During the collection period, the LDC collected a total of 1309 calls, or 2618 sides (1957 GSM), from 254 participants (129 Male, 125 Female), under varied environmental conditions. More information regarding Switchboard Cellular Part 1 is available in swb_stat.html.

Additional information, updates, and other addenda may be available at the LDC catalog entry for this corpus at LDC2001S13.


Please see master.tbl for the directory structure of this publication, as well as a complete list of files. A list of local data files is available at data.

Each speech file consists of a 1024-byte ASCII-formatted Sphere header, followed by 2-channel interleaved mu-law sample data. The mu-law samples represent the actual digital data transmission from the telephone service provider (MCI), as captured separately for each side of the telephone conversation by the LDC's telephone collection platform. The header also indicates the caller_pin, callee_pin, topic_id, cellular service/handset information and speaker demographic information.

The speech files are named according to the following pattern:

where the five-digit string "NNNNN" represents the conversation-id; this string is used to identify all speech files and to identify the calls in the associated data base tables that provide information about the calls and participants (i.e. callstat.tbl, master.tbl).

Other documentation files available are:

description.txt A description of the files.
README Field information for all database tables.
stats.txt Call statistics.
swb_audit.tbl Audit results for each channel.
swb_callstats.tbl Information about recorded calls.
swb_callsubjects.tbl Demographic information.
swb_phones.tbl Handset information.
topics.txt List of proposed call topics.

Content Copyright

Portions © 1999-2001 Trustees of the University of Pennsylvania

Contact: ldc@ldc.upenn.edu
© 2001 Linguistic Data Consortium, Trustees of the University of Pennsylvania. All Rights Reserved.