Logbook: Extremely Long-form Audio Event Understanding
Organizations: UT Austin, USA · Meta Reality Labs, USA
Abstract
Audio benchmarks are built around short, pre-segmented clips, limiting model design to brief inputs or fixed vocabularies. To close this gap, we introduce Logbook, a benchmark for hour-scale audio understanding, with recordings ranging from ten minutes to six days. Given a continuous audio recording and an event label vocabulary, a system must predict a gap-free segmentation with an event label and a description per segment. We compare 52 systems, end-to-end and cascaded, and ablate fine-tuning, context length, and reasoning budget. We find the task tractable, though the best systems remain below the human reference. Also, over-segmentation is pervasive, and fine-tuning partially mitigates it. Finally, end-to-end are often better than cascaded systems, but degrades with longer context.
Figures & tables
| Source | Split | # sess. | Avg. len. | Tot. len. | Label | Domain | # subj. |
|---|---|---|---|---|---|---|---|
| Ego4D | Train | 1350 | 24.7 min | 555.8 h | Inferred | Egocentric | 250 |
| Ego4D | Val | 247 | 26.1 min | 107.6 h | Inferred | Egocentric | 71 |
| Ego4D | Test | 163 | 30.2 min | 82.1 h | Inferred | Egocentric | 55 |
| EgoLife | Test | 170 | 84.9 min | 240.6 h | Inferred | Egocentric | 6 |
| SINS | Test | 1 | 148.9 h | 148.9 h | Provided | Smart home | 1 |
| Ego4D | SINS | EgoLife | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Segmentation | Description | Utility | Segmentation | Segmentation | Description | |||||||||||||
| Model | PFLOPs | bF1 | evER | fAcc | dR | dP | dF1 | Hit | Rddc | bF1 | evER | fAcc | bF1 | evER | fAcc | dR | dP | dF1 |
| EnCLAP | 6.41 | 0.480 | 2.528 | 0.320 | 0.222 | 0.164 | 0.188 | 0.151 | 0.349 | 0.444 | 2.072 | 0.287 | 0.409 | 2.623 | 0.308 | 0.080 | 0.504 | 0.138 |
| MSCLAP | 0.48 | 0.487 | 2.618 | 0.287 | 0.219 | 0.156 | 0.181 | 0.142 | 0.308 | 0.394 | 2.661 | 0.395 | 0.432 | 2.606 | 0.302 | 0.078 | 0.468 | 0.132 |
| Qwen 2.5-o | 43.01 | 0.491 | 3.519 | 0.295 | 0.240 | 0.146 | 0.181 | 0.150 | 0.282 | 0.432 | 2.613 | 0.395 | 0.450 | 4.205 | 0.288 | 0.093 | 0.427 | 0.150 |
| Qwen 3-o | 6.69 | 0.502 | 4.444 | 0.313 | 0.283 | 0.140 | 0.186 | 0.161 | 0.282 | 0.358 | 3.864 | 0.354 | 0.460 | 4.877 | 0.295 | 0.114 | 0.426 | 0.178 |
| Ego4D | SINS | EgoLife | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Segmentation | Description | Utility | Segmentation | Segmentation | Description | |||||||||||||
| Model | PFLOPs | bF1 | evER | fAcc | dR | dP | dF1 | Hit | Rddc | bF1 | evER | fAcc | bF1 | evER | fAcc | dR | dP | dF1 |
| K2-V2 | 62.11 | 0.404 | 1.773 | 0.117 | 0.107 | 0.106 | 0.101 | 0.061 | 0.223 | 0.244 | 1.277 | 0.186 | 0.322 | 1.526 | 0.117 | 0.035 | 0.402 | 0.063 |
| OLMo 3.1 | 18.77 | 0.496 | 3.685 | 0.179 | 0.221 | 0.157 | 0.184 | 0.139 | 0.331 | 0.332 | 3.339 | 0.219 | 0.498 | 4.685 | 0.170 | 0.100 | 0.483 | 0.165 |
| Qwen 2.5 | 39.60 | 0.492 | 3.361 | 0.367 | 0.270 | 0.141 | 0.183 | 0.172 | 0.282 | 0.423 | 3.484 | 0.337 | 0.436 | 3.683 | 0.352 | 0.099 | 0.448 | 0.160 |
| Llama 3.3 | 41.36 | 0.500 | 4.565 | 0.363 | 0.272 | 0.151 | 0.193 | 0.162 | 0.351 | 0.332 | 4.688 | 0.331 | 0.471 | 4.724 | 0.369 | 0.111 | 0.457 | 0.178 |
| Ego4D | SINS | EgoLife | ||||||||||||||||
| Segmentation | Description | Utility | Segmentation | Segmentation | Description | |||||||||||||
| System | PFLOPs | bF1 | evER | fAcc | dR | dP | dF1 | Hit | Rddc | bF1 | evER | fAcc | bF1 | evER | fAcc | dR | dP | dF1 |
| Casc. Gemini 3.5 | — | 0.493 | 2.319 | 0.397 | 0.276 | 0.175 | 0.215 | 0.198 | 0.340 | 0.612 | 1.133 | 0.571 | 0.429 | 2.686 | 0.325 | 0.087 | 0.512 | 0.149 |
| Casc. GPT 5.6 | — | 0.500 | 2.863 | 0.383 | 0.273 | 0.182 | 0.218 | 0.191 | 0.340 | 0.640 | 1.284 | 0.527 | 0.428 | 3.429 | 0.327 | 0.096 | 0.510 | 0.162 |
| Casc. Gemma 4 | 71.41 | 0.508 | 2.608 | 0.398 | 0.262 | 0.218 | 0.238 | 0.160 | 0.304 | 0.547 | 1.588 | 0.512 | 0.430 | 2.822 | 0.311 | 0.085 | 0.560 | 0.147 |
| SFT | 71.12 | 0.247 | 0.785 | 0.520 | 0.316 | 0.403 | 0.355 | 0.180 | 0.207 | 0.573 | 0.668 | 0.421 | 0.254 | 0.756 | 0.335 | 0.044 | 0.706 | 0.084 |
Appendix figures & tables8 assets
Supplementary material from the paper’s appendix.
Appendix
| Ego4D | EgoLife | SINS | |||||
| System | Window | Cnt. | Len. | Cnt. | Len. | Cnt. | Len. |
| Casc. Gemini 3.5 | 5min | 1.84 | 162 | 1.57 | 191 | 0.88 | 341 |
| 10min | 1.26 | 236 | 1.12 | 267 | 0.57 | 525 | |
| 20min | 1.08 | 275 | 0.90 | 330 | 0.43 | 695 | |
| 30min | 1.05 | 282 | 0.90 | 332 | 0.43 | 697 | |
| 45min | 1.05 | 283 | 0.90 | 328 | 0.46 | 659 | |
| System | Ego4D | EgoLife |
|---|---|---|
| Casc. Gemini 3.5 | 9.17 | 9.21 |
| Casc. GPT 5.6 | 18.75 | 18.94 |
| Casc. Gemma 4 | 9.89 | 10.06 |
| + SFT | 4.62 | 4.91 |
| E2E Gemini 3.5 | 8.50 | 10.10 |
| E2E Qwen 3-o | 9.72 | 10.61 |
| Ego4D | EgoLife | SINS | ||||
| System | Cnt. | Len. | Cnt. | Len. | Cnt. | Len. |
| Casc. Gemini 3.5 | 1.26 | 236 | 1.12 | 267 | 0.57 | 525 |
| Casc. GPT 5.6 | 1.51 | 195 | 1.31 | 223 | 0.63 | 474 |
| Casc. Gemma 4 | 1.40 | 214 | 1.17 | 256 | 0.73 | 412 |
| + SFT | 0.30 | 995 | 0.23 | 1296 | 0.21 | 1403 |
| E2E Gemini 3.5 | 0.66 | 384 | 0.64 | 384 | 0.95 | 307 |
| System | Budget | Ego4D | EgoLife | SINS |
|---|---|---|---|---|
| Casc. Gemini 3.5 | None | 0.6% | 0.2% | 0.0% |
| 1024 | 1.7% | 3.0% | 0.9% | |
| 2048 | 2.4% | 2.8% | 0.9% | |
| 4096 | 49.2% | 48.2% | 31.1% | |
| Casc. GPT 5.6 | None | 0.5% | 0.1% | 0.0% |
| Low | 1.3% | 0.9% | 0.4% |
| Ego4D | SINS | EgoLife | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Segmentation | Description | Utility | Segmentation | Segmentation | Description | |||||||||||||
| Audio Cap. | Text model | bF1 | evER | fAcc | R | P | F1 | Hit | rddc | bF1 | evER | fAcc | bF1 | evER | fAcc | R | P | F1 |
| EnCLAP | K2-V2 | 0.445 | 1.796 | 0.189 | 0.156 | 0.120 | 0.136 | 0.087 | 0.277 | 0.301 | 1.364 | 0.243 | 0.372 | 1.829 | 0.219 | 0.059 | 0.482 | 0.105 |
| OLMo 3.1 | 0.491 | 2.919 | 0.177 | 0.189 | 0.150 | 0.168 | 0.152 | 0.344 | 0.361 | 2.863 | 0.172 | 0.496 | 3.902 | 0.212 | 0.089 | 0.510 | 0.151 | |
| Qwen 2.5 | 0.481 | 2.375 | 0.374 | 0.238 | 0.163 | 0.194 | 0.176 | 0.337 | 0.497 | 2.229 | 0.185 | 0.381 | 2.354 | 0.330 | 0.078 | 0.518 | 0.135 | |
| Llama 3.3 | 0.501 | 3.830 | 0.366 | 0.247 | 0.149 | 0.186 | 0.163 | 0.383 | 0.361 | 3.613 | 0.247 | 0.438 | 3.040 | 0.376 | 0.096 | 0.465 | 0.160 | |
| Ego4D | Cascaded | End-to-end | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Class | Ratio | Gemini 3.5 | GPT 5.6 | Gemma 4 | Gemma 4 + SFT | Gemini 3.5 | Qwen 3-o | Qwen 3-o + SFT | Qwen 2.5-o |
| productive | 0.401 | 0.369 | 0.336 | 0.324 | 0.603 | 0.503 | 0.269 | 0.763 | 0.945 |
| leisure | 0.285 | 0.601 | 0.616 | 0.688 | 0.695 | 0.513 | 0.841 | 0.680 | 0.017 |
| food | 0.117 | 0.460 | 0.408 | 0.451 | 0.532 | 0.447 | 0.229 | 0.646 | 0.000 |
| traveling | 0.082 | 0.157 | 0.164 | 0.138 | 0.054 | 0.114 | 0.042 | 0.211 | 0.132 |
| other | 0.059 | 0.086 | 0.133 | 0.055 | 0.000 | 0.191 | 0.264 | 0.000 | 0.000 |