ASVspoof 2021: 54 teams' spoofed and deepfake speech detectors across logical access, physical access and deepfake tasks
- Authors
- Liu, Wang, Sahidullah, Patino, Delgado, Kinnunen, Todisco, Yamagishi, Evans, Nautsch, Lee
- Venue
- IEEE/ACM Transactions on Audio, Speech, and Language Processing 31, pages 2507 to 2522
- Published
ASVspoof 2021, the fourth challenge in the speech anti-spoofing series, scored valid submissions from 54 teams across three tasks and found that the best logical access (LA) detector, team T23, reached a pooled min t-DCF of 0.2177 and an equal error rate of 1.32% on 148,176 evaluation trials, that the best physical access (PA) detector, T07, reached 0.6824 and 24.25% on 721,332 trials, and that the best detector in the new deepfake (DF) task, again T23, reached an EER of 15.64% on 533,928 compressed trials against 22.38% for the best organiser baseline (arXiv 2210.02437, Tables I, XIV, XV and XVI, read 10 November 2026). The summary paper, "ASVspoof 2021: Towards Spoofed and Deepfake Speech Detection in the Wild" by Xuechen Liu, Xin Wang, Md Sahidullah, Jose Patino, Héctor Delgado, Tomi Kinnunen, Massimiliano Todisco, Junichi Yamagishi, Nicholas Evans, Andreas Nautsch and Kong Aik Lee, was published in IEEE/ACM Transactions on Audio, Speech, and Language Processing, volume 31, pages 2507 to 2522, in 2023, Crossref record created 19 June 2023 (DOI 10.1109/TASLP.2023.3285283, read 10 November 2026); the arXiv version 3 of 22 June 2023, with its supplementary material, was read in full.
The record is the second voice entry in the studies index, two editions before ASVspoof 5. No product sold under a card in this index is a named participant.
Participants, not products, are the detectors here: 54 teams submitted valid scores and 34 the required system description, from 72 registered; teams are identified only by number, and unlabelled rows in the result tables sent no description (arXiv 2210.02437, Section VII, Acknowledgements and Fig. 3 caption, read 10 November 2026). Four organiser baselines were scored in every task.
What was tested
Detectors tested
| Detector (team ID, rank, task) | System as described in Table V | Index card |
|---|---|---|
| T23 (1st LA, 1st DF, 3rd PA) | Transmission and media codec augmentation; raw waveform and spectrogram; LightCNN, ResNet and LSTM fusion | no card |
| T35 (2nd LA) | Additive noise; LFCC; ResNet | no card |
| T19 (3rd LA) | RIR and MUSAN augmentation; Mel spectrogram; ResNet and SEnet | no card |
| T07 (1st PA) | Speed perturbation; log spectrogram; VAE and GMM | no card |
| T16 (2nd PA) | In-house replay; linear, raw and phase spectra; SEnet | no card |
| T20 (2nd DF) | RIR, MUSAN and media codec; linear filter bank; ResNet and MLP | no card |
| T08 (3rd DF) | Transmission and media codec; CQT spectrogram; LightCNN | no card |
| B01 CQCC-GMM, B02 LFCC-GMM, B03 LFCC-LCNN-LSTM, B04 RawNet2 | organisers' baselines | no card |
Sample
Ranks from Tables XIV to XVI and descriptions from Table V of arXiv 2210.02437.
None of the voice cards in this index, Pindrop Pulse, Resemble Detect, Reality Defender, Hive, Sensity, ElevenLabs or AI or Not, appears as a participant. Deepfake-O-Meter hosts research implementations of RawNet2 and LFCC-LCNN trained on ASVspoof data, architectures shared with the baselines, not scored challenge entries. The paper cites a Pindrop blog post as background and prints no Pindrop result (arXiv 2210.02437, reference 6, read 10 November 2026).
All data are English read speech from the VCTK corpus. The LA task passes the ASVspoof 2019 LA attacks through real telephony in seven conditions, from uncoded 16 kHz audio through a-law, G.722, mu-law, GSM and OPUS codecs over VoIP and an uncontrolled PSTN leg, with three conditions unseen before evaluation. The PA task replays speech in nine real rooms. The DF task, new in 2021, adds bona fide and spoofed speech from the 2018 and 2020 Voice Conversion Challenges, compressed with mp3, m4a and ogg at two bit rates each plus two double-codec conditions (arXiv 2210.02437, Section II and Tables I to IV, read 10 November 2026). Training used only the 2019 data, so the VCC sources were unseen.
The LA and PA metric is the pooled normalised minimum t-DCF, which scores the detector in tandem with a fixed speaker verification system, with EER also printed; the DF task has no verification system and is scored by EER alone (arXiv 2210.02437, Section II, read 10 November 2026).
What the study reports
| Metric | Value | Base |
|---|---|---|
| LA, top five min t-DCF and EER (Table XIV, evaluation) | T23 0.2177, 1.32%; T35 0.2480, 2.77%; T19 0.2495, 3.13%; unlabelled 0.2500, 2.81%; T36 0.2531, 3.10% | 148,176 LA evaluation trials |
| LA baselines (Table XIV) | B03 0.3445, 9.26%; B04 0.4257, 9.50%; B01 0.4974, 15.62%; B02 0.5758, 19.30% | 148,176 LA evaluation trials |
| PA, top three (Table XV, evaluation) | T07 0.6824, 24.25%; T16 0.7122, 27.59%; T23 0.7296, 26.42%; ASV floor 0.12 (Section III-B) | 721,332 PA evaluation trials |
| PA baselines (Table XV) | B01 0.9434, 38.07%; B02 0.9724, 39.54%; B03 0.9958, 44.77%; B04 0.9997, 48.60% | 721,332 PA evaluation trials |
| DF, top five EER (Table XVI, evaluation) | T23 15.64%; T20 16.05%; T08 18.30%; unlabelled 18.80%; T06 19.01% | 533,928 DF evaluation trials |
| DF baselines (Table XVI) | B04 22.38%; B03 23.48%; B02 25.25%; B01 25.56% | 533,928 DF evaluation trials |
| DF progress versus evaluation (Section III-C) | 23 of 33 systems under 10% EER on progress, best under 1% (T23 0.24%); all above 15% on evaluation; 18 beat B04 | 59,325 progress and 533,928 evaluation trials |
| DF EER by bona fide source (Table VI) | T23 15.63% all, 23.39% with VCC 2018 bona fide, 0.33% with 2019 LA bona fide and spoof only | DF evaluation subsets |
| Post-challenge wav2vec 2.0 system (Table VIII, reference 42) | LA 0.2066, 0.82%; DF 2.85% | same evaluation sets |
Every figure below is printed in Tables XIV to XVI of the supplementary material or in Tables VI, VIII and X of the paper.
Values as printed in arXiv 2210.02437, Tables VI, VIII, X and XIV to XVI, read 10 November 2026. Table VIII prints T23's LA min t-DCF as 0.2176 and Table VI its DF EER as 15.63%, against 0.2177 and 15.64% in the supplementary tables.
Three findings carry beyond the leaderboard. First, telephony did little harm in the LA task: transmission across real telephone systems "causes only modest degradation", though the voice conversion attack A18 rose from a median t-DCF of about 0.4 uncoded to over 0.8 after the unknown PSTN leg (arXiv 2210.02437, Sections III-A and VII, read 10 November 2026). Second, the DF task exposed a source mismatch rather than a codec problem: EERs for the VCC source data were "substantially higher" than for ASVspoof 2019 data, and when VCC bona fide trials were excluded T23's EER fell below 1%, which the authors trace to a shift in bona fide score distributions and "over-fitting" to the 2019 training corpus (arXiv 2210.02437, Section IV-C and Table VI, read 10 November 2026).
Third, silence was a cue. On hidden subsets with non-speech intervals removed, top LA and DF systems that were under 10% EER rose above 20%, and trimming only the leading and trailing silence took B04's LA min t-DCF from 0.426 to 0.908; four of the top ten PA systems scored above 0.99 on a simulated replay subset, which the authors say cautions against simulated evaluation data (arXiv 2210.02437, Sections IV-A and IV-B, Table X and supplementary Section X, read 10 November 2026).
Limits the authors state
Section VI lists them: the data are "exclusively English-language, read-speech sourced from the VCTK corpus"; the LA and DF attacks were state of the art "prior to 2020"; the strict training policy excluded the external pre-training that post-challenge systems used to reach 0.82% LA EER; non-speech length "should not serve as a cue for detection"; only fully spoofed utterances were scored, not partial spoofs; and adversarial attacks on the detector were out of scope (arXiv 2210.02437, Section VI, read 10 November 2026). The DF task also lacked a human-listener leg, which the authors suggest for future tandem assessment.
Evident from the paper: per-team results sit in the supplementary tables, with the main text showing bar charts; 20 of the 54 teams are unlabelled; and nothing identifies a commercial product.
Which cards this study feeds
- No card in the index was tested by this record.
- AIDI-R-07AI image, voice, video and code detectors ranked by independent studies
- AIDI-R-02AI detector false positive rates, ranked
No card takes a result line from this record, because no indexed product is a scored participant. The record counts toward the voice column of studies by modality as a record with zero indexed detectors, and the content type view lists the cards that state voice. No figure enters the false positive rate ranking, which ranks cards. The home page lists which AI detectors exist and who has tested them.
Related records: ASVspoof 5 is the 2024 edition, where the best open-condition detector reached 2.59% EER and again posted 10% to 27% on other databases; SAFE 2025 is the index's other audio challenge, with named teams; DFDC 2020 is the video counterpart.
Questions about this study
What was the best result in ASVspoof 2021?
A pooled min t-DCF of 0.2177 and an EER of 1.32% by team T23 in the logical access task on 148,176 evaluation trials; T23 also led the deepfake task at 15.64% EER on 533,928 trials, and T07 led physical access at 0.6824 and 24.25% (arXiv 2210.02437, Tables XIV to XVI).
Why were deepfake-task error rates so much higher than logical access?
Because the deepfake evaluation added speech from the 2018 and 2020 Voice Conversion Challenges, sources absent from training: 23 of 33 systems were under 10% EER on the progress subset but all exceeded 15% on evaluation, and T23 fell to 0.33% when only ASVspoof 2019 source data were scored (arXiv 2210.02437, Section III-C and Table VI).
Did any commercial voice detector take part in ASVspoof 2021?
None is named: the 54 teams appear as numbered IDs and no card in this index appears among them; a Pindrop blog post is cited only as background (arXiv 2210.02437, Fig. 3 caption and reference 6).
How did silence affect ASVspoof 2021 detectors?
Removing non-speech intervals raised top LA and DF systems from under 10% EER to over 20% on the hidden tracks, and trimming only the leading and trailing silence took the RawNet2 baseline's LA min t-DCF from 0.426 to 0.908 (arXiv 2210.02437, Table X and supplementary Section X).
Source and revisions
Source
Liu, X., Wang, X., Sahidullah, M., Patino, J., Delgado, H., Kinnunen, T., Todisco, M., Yamagishi, J., Evans, N., Nautsch, A., Lee, K. A. (2023). ASVspoof 2021: Towards Spoofed and Deepfake Speech Detection in the Wild. IEEE/ACM Transactions on Audio, Speech, and Language Processing 31, 2507 to 2522, DOI 10.1109/TASLP.2023.3285283; read as arXiv:2210.02437 v3 (22 June 2023, with supplementary material), https://arxiv.org/abs/2210.02437 and https://arxiv.org/pdf/2210.02437, both read 10 November 2026. Journal record: Crossref https://api.crossref.org/works/10.1109/TASLP.2023.3285283, read 10 November 2026.


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