File size: 5,832 Bytes
4cb4e57
 
 
fbc026a
 
 
 
 
 
 
 
 
 
 
 
269df36
4cb4e57
fbc026a
562d463
 
fbc026a
c41893d
fbc026a
c305059
ba01d5d
c41893d
cddf408
c41893d
c305059
1ea44f4
c305059
 
ba01d5d
 
 
 
 
 
 
 
 
 
52b1e68
ad24938
ba01d5d
 
 
 
0022abf
ba01d5d
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
c305059
 
c41893d
ba01d5d
 
52b1e68
ad24938
ba01d5d
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
c41893d
 
ba01d5d
c305059
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
---
license: cc-by-sa-4.0
language:
  - it
  - pt
  - es
  - fr
  - de
  - vi
  - id
  - ru
  - en
  - zh
task_categories:
  - text-to-speech
  - automatic-speech-recognition
size_categories:
  - n>1T
---

## Overview

This dataset is part of **LEMAS (Large-scale Extensible Multilingual Audio Suite)**.
It contains a large-scale training set (150k+ hours) and a curated evaluation set
(500 utterances per language) covering 10 languages, all with word-level alignment.


## Fields
- `key`: unique utterance identifier; the first two characters indicate the language ID
- `audio`: relative path to the MP3 audio file (in the eval set, this key is renamed to "file_name" for compatibility with the viewer)
- `dur`: audio duration in seconds
- `txt`: original transcription
- `align`: alignment information, including:
  - `align.txt`: normalized text used for alignment
  - `align.words`: list of word-level timestamps and confidence scores



## Methods

### Train Set

- The training set is constructed by filtering large-scale aligned audio–text pairs with language- and dataset-specific constraints.
- URL: [https://huggingface.co/datasets/LEMAS-Project/LEMAS-Dataset-train](https://huggingface.co/datasets/LEMAS-Project/LEMAS-Dataset-train)

**Filtering rules:**
- Only samples with successfully extracted word-level alignments are kept; failed alignments are skipped.
- The average alignment confidence score is greater than a threshold **x**, where **x ∈ [0.2, 0.5]** depending on the source dataset.
- Audio duration is between **0.5 and 30 seconds**, and the maximum pause between consecutive words does not exceed **4 seconds**.
- Text is restricted to supported languages; samples containing characters outside the supported set (10 languages) are removed.
- The text-to-duration ratio `len(txt) / dur` falls within a language-specific range.


#### **Statistics**
| lang | utterances | total_dur(h) | avg_dur(s) | total_chars | avg_chars | char/sec | total_words | avg_words | word/sec |
|------|-----------:|-------------:|-----------:|------------:|----------:|---------:|------------:|----------:|---------:|
| it   |    7209567 |      6116.69 |      3.054 |   281128388 |    38.994 |  12.7669 |    48859270 |     6.777 |   2.2188 |
| fr   |    7557428 |      6535.94 |      3.113 |   344633332 |    45.602 |  14.6469 |    65843169 |     8.712 |   2.7983 |
| vi   |    6426292 |      6600.07 |      3.697 |   387621747 |    60.318 |  16.3139 |    89903814 |    13.990 |   3.7838 |
| pt   |    8682442 |      7384.42 |      3.062 |   339417251 |    39.092 |  12.7678 |    60316112 |     6.947 |   2.2689 |
| de   |   11003833 |      9842.14 |      3.220 |   487581808 |    44.310 |  13.7612 |    80119609 |     7.281 |   2.2612 |
| id   |   11659550 |     11246.27 |      3.472 |   543857918 |    46.645 |  13.4331 |    85967394 |     7.373 |   2.1234 |
| es   |   26407271 |     21224.55 |      2.893 |  1011116926 |    38.289 |  13.2331 |   183673862 |     6.955 |   2.4038 |
| ru   |   27474400 |     22919.31 |      3.003 |   991530233 |    36.089 |  12.0172 |   163018329 |     5.933 |   1.9758 |
| en   |    9515267 |     25347.90 |      9.590 |  1419864294 |   149.220 |  15.5597 |   268676221 |    28.236 |   2.9443 |
| zh   |   17776663 |     32919.28 |      6.667 |  2474249286 |   139.185 |  20.8781 |   496957308 |    27.956 |   4.1934 |

Words and chars statistics are computed based on the normalized alignment text (`align.txt`).

### Eval Set

- The eval set is built by filtering, trimming, and ranking aligned audio–text pairs.
- URL: [https://huggingface.co/datasets/LEMAS-Project/LEMAS-Dataset-eval](https://huggingface.co/datasets/LEMAS-Project/LEMAS-Dataset-eval)

**Filtering rules:**
- Average word-level alignment score > **0.9**
- Number of aligned words > **5**
- Duration between **3 and 15 seconds**
- Sentence-end silence is trimmed to at most **0.2s**

**Selection:**
- Samples are ranked by  
  `final_score = edge_gap × density_diff`, where  
  `edge_gap = words[0].start + (dur - words[-1].end)` and  
  `density_diff = |len(align_txt)/dur − global_mean_density|`

#### **Statistics**

| lang | utterances | total_dur(min) | avg_dur(s) | total_chars | avg_chars | char/sec | total_words | avg_words | word/sec |
|------|-----------:|---------------:|-----------:|------------:|----------:|---------:|------------:|----------:|---------:|
| it   |        500 |          44.22 |      5.306 |       40388 |     80.78 |   15.22  |        6599 |     13.20 |   2.49   |
| fr   |        500 |          38.17 |      4.580 |       38098 |     76.20 |   16.64  |        6546 |     13.09 |   2.86   |
| vi   |        500 |          36.74 |      4.409 |       28546 |     57.09 |   12.95  |        6727 |     13.45 |   3.05   |
| pt   |        500 |          41.69 |      5.003 |       33343 |     66.69 |   13.33  |        5812 |     11.62 |   2.32   |
| de   |        500 |          38.65 |      4.638 |       36571 |     73.14 |   15.77  |        5599 |     11.20 |   2.41   |
| id   |        500 |          47.20 |      5.665 |       41026 |     82.05 |   14.49  |        6133 |     12.27 |   2.17   |
| es   |        500 |          40.52 |      4.862 |       37075 |     74.15 |   15.25  |        6216 |     12.43 |   2.56   |
| ru   |        500 |          40.24 |      4.828 |       33886 |     67.77 |   14.04  |        5138 |     10.28 |   2.13   |
| en   |        500 |          67.46 |      8.095 |       62449 |    124.90 |   15.43  |       11325 |     22.65 |   2.80   |
| zh   |        500 |          75.84 |      9.101 |       95669 |    191.34 |   21.02  |       18627 |     37.25 |   4.09   |

Statistics are computed based on trimmed audio and normalized alignment text (`align.txt`).


## Notes

- We will complete further updates and release a technical report soon.