diarray commited on
Commit
8679523
·
verified ·
1 Parent(s): a88276c

Update README.md

Browse files
Files changed (1) hide show
  1. README.md +121 -2
README.md CHANGED
@@ -80,5 +80,124 @@ tags:
80
  - RobotsMali
81
  - afvoices
82
  - asr
83
- pretty_name: a
84
- ---
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
80
  - RobotsMali
81
  - afvoices
82
  - asr
83
+ pretty_name: Robots
84
+ ---
85
+
86
+ # 📘 **African Next Voices – Bambara (AfVoices)**
87
+
88
+ The **AfVoices** dataset is the largest open corpus of spontaneous Bambara speech at its release in late 2025. It contains **423 hours** of segmented audio and **612 hours** of original raw recordings collected across southern Mali. Speech was recorded in natural, conversational settings and annotated using a semi-automated transcription pipeline combining ASR pre-labels and human corrections.
89
+
90
+ ---
91
+
92
+ ## 🔎 **Quick Facts**
93
+
94
+ | Category | Value |
95
+ | ---------------------------------------- | ------------------------------------------------------------------------------------------------- |
96
+ | **Total raw hours** | 612 h (1,777 raw recordings; publicly available on GCS) |
97
+ | **Total segmented hours** | 423 h (874,762 segments) |
98
+ | **Speakers** | 512 |
99
+ | **Regions** | Bamako, Ségou, Sikasso, Bagineda, Bougouni |
100
+ | **Avg. segment duration** | ~2 seconds |
101
+ | **Subsets** | 159 h human-corrected, 212 h model-annotated, 52 h short (<1s) |
102
+ | **Age distribution** | Broad, across young to elderly speakers (90% between 18 and 45) |
103
+ | **Topics** | Health, agriculture, Miscellaneous (art, education, history etc.) |
104
+ | **SNR distribution (raw recordings)** | 71.75% High or Very High SNR |
105
+ | **Train / Test split** | 155 h / 4 h |
106
+
107
+ ---
108
+
109
+ ## **Motivation**
110
+
111
+ The **African Next Voices (ANV)** project is a multi-country effort aiming to gather over **9,000 hours of speech** across 18 African languages. Its goal is to build high-quality datasets that empower local communities, support inclusive AI research, and provide strong foundations for ASR in underrepresented languages.
112
+
113
+ As part of this initiative, **RobotsMali** led the Bambara data collection for Mali. This dataset reflects RobotsMali’s broader mission to advance AI and NLP research malian languages, with a long-term focus on improving education, access, and technology across Mali and the wider Manding linguistic region.
114
+
115
+ ---
116
+
117
+ ## 🎙️ **Characteristics of the Dataset**
118
+
119
+ ### **Data Collection**
120
+
121
+ * Speech was collected through trained **facilitators** who guided participants, ensured audio quality, and encouraged natural, topic-focused conversations.
122
+ * All recordings are **spontaneous speech**, not read text.
123
+ * A custom **Flutter mobile app** ([open-source](https://github.com/RobotsMali-AI/Africa-Voice-App)) was used to simplify the process and reduce training time.
124
+ * Geographic focus: **Southern Mali**, to limit extreme accent variation and build a clean baseline corpus.
125
+
126
+ ### **Segmentation and Preprocessing**
127
+
128
+ * Raw audio was segmented using **Silero VAD**, retaining ~70% of the original duration.
129
+ * Segments range from **240 ms to 30 s**.
130
+ * Voice activity detection helped remove long silences and improve data usability.
131
+
132
+ ### **Transcriptions**
133
+
134
+ * Pre-transcribed using the ASR model **soloni-114m-tdt-ctc-v0**.
135
+ * Human annotators corrected the transcripts.
136
+ * A second model (**soloni-114m-tdt-ctc-v2**) was trained using the corrected transcripts and used to regenerate improved labels.
137
+ * Two automatic transcription variants exist for each sample: **v1** (from soloni-v0) and **v2** (from soloni-v2).
138
+
139
+ ### **Acoustic Event Tags**
140
+
141
+ The following tags appear in transcriptions:
142
+
143
+ | Tag | Meaning |
144
+ | --------- | ------------------------------------------------------------- |
145
+ | `[um]` | Vocalized pauses, filler sounds |
146
+ | `[cs]` | Code-switched or foreign word |
147
+ | `[noise]` | Background noise (applause, coughing, children, etc.) |
148
+ | `[?]` | Inaudible or overlapped speech |
149
+ | `[pause]` | Long silence (>5 seconds or >3 seconds at segment boundaries); due to VAD segmentation this tag is rarely used |
150
+
151
+ ---
152
+
153
+ ## 📂 **Subsets**
154
+
155
+ ### **1. Human-corrected (159 h, 260k samples)**
156
+
157
+ * Fully reviewed and corrected by annotators.
158
+ * Only subset with a definitive `text` field containing the validated transcription.
159
+
160
+ ### **2. Model-annotated (212 h, 355k samples)**
161
+
162
+ * Includes automatic labels: `v1` (soloni-v0) and `v2` (soloni-v2).
163
+ * No human review.
164
+
165
+ ### **3. Short subset (52 h, 259k samples)**
166
+
167
+ * Segments <1 second (formulaic expressions, discourse markers).
168
+ * Excluded from human annotation for optimization purposes.
169
+ * Automatically labeled (v1 & v2).
170
+
171
+ ---
172
+
173
+ ## ⚠️ **Limitations**
174
+
175
+ * **Clean dataset vs real-world noise:**
176
+ Over 70% of recordings can be categorized as relatively clean speech. Models trained solely on this dataset may underperform in noisy street or radio environments typical in Mali. See this [report](https://zenodo.org/records/17672774) if you are interested in learning more about the strengths and weaknesses of RobotsMali's ASR models.
177
+
178
+ * **Reduced code-switching:**
179
+ French terms were often replaced by `[cs]` or normalized into Bambara phonology. This improves model stability but reduces realism for natural bilingual speech.
180
+
181
+ * **Geographic homogeneity:**
182
+ Focused on the southern region to control accent variability. Broader dialectal coverage might require additional data.
183
+
184
+ * **Simplified linguistic conditions:**
185
+ Overlaps, multi-speaker settings, and conversational chaos are minimized—again improving training stability at the cost of deployment realism.
186
+
187
+ ---
188
+
189
+ ## 📑 **Citation**
190
+
191
+ ```bibtex
192
+ @article{diarra2025afvoices,
193
+ title={Dealing with the Hard Facts of Low-Resource African NLP},
194
+ author={Diarra, Yacouba and Coulibaly, Nouhoum Souleymane and Kamaté, Panga Azazia and Tall, Madani Amadou and Koné, Emmanuel Élisé and Dembélé, Aymane and Leventhal, Michael},
195
+ journal={Preprint},
196
+ note = {arxiv coming soon}
197
+ year={2025},
198
+ }
199
+ ```
200
+
201
+ ---
202
+
203
+ You may want to download the original 612 hours dataset with its associated metadata for research purposes or to create a derivative. You will find the codes and manifest files to download those files from Google Cloud Storage in this repository: [RobotsMali-AI/afvoices](https://github.com/RobotsMali-AI/afvoices). Do not hesitate to open an issue for Help or suggestions 🤗