CORPORA from CSLU: Speaker recognition v1.1

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The Speaker Recognition corpus (formerly known as Speaker Verification), consists of telephone speech from 91 participants. Each participant has recorded speech in twelve sessions over a two-year period answering questions like "what is your eye color" or respond to prompts like "describe a typical day in your life." Most of the utterances in the release of the corpus have corresponding non-time-aligned word level transcriptions.


Collection Method:

In most of the CSLU data collections, each participant calls a toll free telephone number and answers a few question. CSLU records the speech, transcribes it, then packages it as a released corpus.

The Speaker Recognition data collection was quite a bit more complicated. The goal of the data collection was to collect speech from each participant over a two year period. Each participant called call the data collection system twelve times over the two-year period and say the same utterances each time.

Some of the recording sessions were only a few days apart and others several weeks apart. Participant followed the following calling schedule. During the first month, they called twice in a week. No calls were made in the second and third months. In the fourth month they made one call. No calls were made in the fifth and sixth months. This pattern repeated three more times for a total of twelve calls per participant.

In order to balance the workload required to remind participants to call and to avoid large data collection bursts on the system, the participants were divided into twelve groups. Each group began the two-year schedule on subsequent months. The first group started in September, 1996. The second group started in October, 1996. And so on.

Participants failing to make the required calls in a timely manner were dropped from the program and not notified of the future calls to make.

Recording conditions:

All of the data in this corpus were collected over digital telephone lines. The digital data were recorded with the CSLU T1 digital data collection system. The .wav files contain speech data and use the RIFF standard file format. This file format is 16-bit linearly encoded.


Subject Population:

Every attempt was made to create a gender balanced subject pool. As each group started the data collection it had an equal number of both genders. However, as participants were dropped, the balance couldn't be perfectly maintained. The release notes with each release show the gender balance for that set of speakers.



Nearly all of the files included in this corpus have corresponding non-time-aligned word-level transcriptions that comply with the conventions in the CSLU Labeling Guide. The current releases have only transcribed some of the long spontaneous utterances.


The Center for Spoken Language Understanding (CSLU) distributes corpora to commercial entities and academic institutions for a fee. Commercial entities can use these corpora for research but also for creating commercial products such as generating acoustic models for speech recognition.


To place your order:

1. Click on the type of license you wish to order: Academic or non-profit entity or Commercial entity.

2. Terms of the license agreement can be viewed by clicking on the word "terms".

3. You agree to the terms of the license agreement when you click on "Add to Order" and proceed to the next screen.

4. If information on the "Order Contents" screen is correct, press "Check out".

5. On the next screen, a brief "Intended Use" is required. For "Recipient Scientist Information" enter the appropriate information for yourself or if you are placing the order for another person enter that information. We will use this information should we have questions about the order, payment or shipping address.

6. Once your payment has been received and verified by OHSU, your order will be approved by Technology Transfer & Business Development and then the DVD will be sent out by the Center for Spoken Language Understanding by FedEx within 5-10 business days.  

For demos and more information, visit the CSLU Corpora website at:


Files will be made available by download from which requires customers to set up a free account. 

Patent Information:
Speech & Language
For Information, Contact:
Arvin Paranjpe
Technology Development Manager
Oregon Health & Science University
(503) 494-8200
Education & Training
Education & Training - Speech & Language
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