Forensic Voice Comparison Databases
  • This website provides databases of audio recordings for forensic-voice-comparison research and practice.


  • The databases are made available to researchers in order to foster research on forensic voice comparison.


  • They are also made available to practitioners in order to assist them to make numeric estimates of likelihood ratios as strength-of-evidence statements in casework, and to test the validity and reliability of forensic-voice-comparison systems under casework conditions.


  • We collect multiple non-contemporaneous recordings of each speaker, and in each recording session collect recordings of different speaking styles.


  • Details of our data-collection protocol and the rationale behind it are presented in:

    • Morrison, G. S., Rose, P., & Zhang, C. (2012). Protocol for the collection of databases of recordings for forensic-voice-comparison research and practice. Australian Journal of Forensic Sciences, 44, 155–167.
      doi:10.1080/00450618.2011.630412


  • The recordings were made in a high-quality format and have been manually processed to remove extraneous noises and crosstalk.

  • The recordings can be further processed to reflect the conditions of particular cases.




last update: 24 December 2015


Forensic Voice Comparison Databases

Australian English: 500+ speakers

  • This database currently contains recordings of 552 Australian English speakers.

    • 322 female speakers

      • 90 recorded on one occasion (session)

      • 72 recorder on two separate occasions

      • 155 recorded on three occasions

      • 5 recorded on more than three occasions

    • 231 male speakers

      • 62 recorded on one occasion

      • 43 recorder on two separate occasions

      • 107 recorded on three occasions

      • 19 recorded on more than three occasions


  • Recordings from some additional speakers will be released at a later date, along with some additional session-task combinations from existing speakers.


  • On each occasion, each speaker was recorded in three speaking styles (tasks):

    • casual telephone conversation (cnv)

    • information exchange task over the telephone (fax)

    • pseudo-police-style interview (int)


  • The database was collected by the

    Forensic Voice Comparison Laboratory, School of Electrical Engineering & Telecommunications, University of New South Wales

    as part of the Australian Research Council funded Linkage Project Making demonstrably valid and reliable forensic voice comparison a practical everyday reality in Australia

    in partnership with:

    • Australian Federal Police

    • New South Wales Police

    • Queensland Police

    • National Institute of Forensic Sciences

    • Australasian Speech Sciences and Technology Association

    • Guardia Civil

    • Universidad Autónoma de Madrid


  • Database collection materials

    • Instuctions for speakers, and faxes


  • Sound file infomation

    • Includes information about how many recording sessions were completed by each speaker.


  • The database is available for download from this site.

    • download database (login required)


    • Internet Explorer users: To view the login request please set the security settings to "Medium High" or lower.


  • Please cite as:

    • Morrison G.S., Zhang C., Enzinger E., Ochoa F., Bleach D., Johnson M., Folkes B.K., De Souza S., Cummins N., Chow D. (2015). Forensic database of voice recordings of 500+ Australian English speakers. [Available: http://databases.forensic-voice-comparison.net/]


  • History:

    • 2015-02-24 initial release

    • 2016-08-12 corrected version – We discovered that the previous version contained several mislabeled folders. These have been manually corrected and checked. If you downloaded before 2016-08-12, we recommend that you discard the earlier version and download the corrected version instead.

    • 2016-08-19 counting error in spreadsheet corrected

    • 2016-08-20 folder 2017(3)_cnv moved from female to male folder (this was a missing folder - it was not listed in the spreadsheet)

    • additional material will be released at a later date



last update: 21 August 2016


Forensic Voice Comparison Databases

forensic_eval_01

Multi-laboratory evaluation of forensic voice comparison systems under conditions reflecting those of a real forensic case

  • There is increasing pressure on forensic laboratories to validate the performance of forensic analysis systems before they are used to assess strength of evidence for presentation in court (including pressure from the recently released report by the President’s Council of Advisors on Science and Technology, PCAST). Different forensic voice comparison systems may use different approaches, and even among systems using the same general approach there can be substantial differences in operational details. From case to case, the relevant population, speaking styles, and recording conditions can be highly variable, but it is common to have relatively poor recording conditions and mismatches between the known- and questioned-speaker recordings. In order to validate a system intended for use in casework, a forensic laboratory needs to evaluate the degree of validity and reliability of the system under forensically realistic conditions. We have released a set of training and test data representative of the relevant population and reflecting the conditions of an actual forensic voice comparison case, and operational forensic laboratories and research laboratories are invited to use these data to train and test their systems. The details below include the rules for the evaluation, a description of the data, and a description of the evaluation metrics and graphics. The name of the evaluation is: forensic_eval_01

  • Papers reporting on the results of the evaluation of each system will be published in a Virtual Special Issue (VSI) of Speech Communication.


  • Details (introductory paper for the VSI)



    • download data (login required)




  • Internet Explorer users: To view the the “request login” link on this page, set the security level to “medium-high” or below

last update: 29 September 2016


Forensic Voice Comparison Databases

Standard Chinese: 68 female speakers

  • This database contains two non-contemporaneous recordings of each of 68 female speakers of Standard Chinese (a.k.a. Mandarin and Putonghua).


  • 60 of the speakers are from north eastern China, and 8 are from southern China.


  • Each speaker was recorded in three speaking styles:

    • casual telephone conversation (cnv)

    • information exchange task over the telephone (fax)

    • pseudo-police-style interview (int)


  • Recordings were made at China Criminal Police University in Shenyang, China, under the supervision of Cuiling Zhang.


  • Data collection was financially supported by an International Association for Forensic Phonetics and Acoustics (IAFPA) Research Grant:

    • Zhang, C., & Morrison, G.S. (2009). Forensic comparison of Chinese female voices. Application for an International Association for Forensic Phonetics and Acoustics Research Grant.
    • download pdf


  • Database collection materials

    • Instuctions for speakers, and faxes


  • Sound file infomation

    • Includes suggested split of NE speakers into background, development, and test sets.


  • The database is available for download from this site.

    • download database (login required)


    • Internet Explorer users: To view the login request please set the security settings to "Medium High" or lower.


  • Please cite as:

    • Zhang, C., & Morrison, G. S. (2011). Forensic database of audio recordings of 68 female speakers of Standard Chinese. [Available: http://databases.forensic-voice-comparison.net/]


  • Release dates:

    • 2011-03-13 original release of high quality audio

    • 2015-02-16 release of “fax” task in telephone-degraded conditions (see Zhang, Morrison, Enzinger, Ochoa, 2013)


  • Related papers include:

    • Zhang, C., Morrison, G.S., Enzinger, E., Ochoa, F. (2013). Effects of telephone transmission on the performance of formant-trajectory-based forensic voice comparison – female voices. Speech Communication, 55, 796–813.
      doi:10.1016/j.specom.2013.01.011

    • Zhang, C., Morrison, G. S., Ochoa, F., Enzinger E. (2013). Reliability of human-supervised formant-trajectory measurement for forensic voice comparison. Journal of the Acoustical Society of America, 133, EL54–EL60.
      doi:10.1121/1.4773223



last update: 16 February 2015