PART I — BEFORE YOU COLLECT ANYTHING

1. Define Why You Are Collecting Voice Data 
 Before recruiting anyone, answer: 
 1.1 What will the data be used for? 
 Examples: 
 
 
 Automatic Speech Recognition 
 
 
 Speech-to-text 
 
 
 Text-to-Speech 
 
 
 Speech translation 
 
 
 Voice assistants 
 
 
 Language documentation 
 
 
 Linguistic research 
 
 
 Benchmarking 
 
 
 Conversational AI 
 
 
 Digital government 
 
 
 Healthcare 
 
 
 Agriculture 
 
 
 Education 
 
 
 Your intended use determines what type of recordings you need. 
 1.2 What kind of speech do you need? 
 There are two basic approaches used in the reference project. 
 a) Scripted speech 
 A participant reads a prepared sentence. 
 b) Unscripted speech 
 A participant responds naturally to a question or prompt. 
 The reference project deliberately combined the two, targeting approximately 75% unscripted and 25% scripted speech. 
 Practical recommendation 
 If your goal is a general-purpose speech dataset, consider collecting both. 
 
 
 
 
 
 Type 
 
 
 What it gives you 
 
 
 
 
 Scripted 
 
 
 Controlled sentences, predictable content 
 
 
 
 
 Unscripted 
 
 
 Natural speech, dialects, spontaneous phrasing 
 
 
 
 
 Both 
 
 
 Broader coverage 
 
 
 
 
 
 Do not assume that one approach automatically replaces the other. 
 2. Decide How Much Data You Need 
 Start with the target rather than starting with recruitment. 
 Define: 
 a)Target number of speakers 
 Example: 1,000 speakers 
 b)Target hours 
 Example : 500 hours 
 c)Target recordings per person 
 Example:  30 minutes validated speech per contributor 
 d)Target speech type 
 Example:  75% unscripted / 25% scripted 
 e)Target geographic coverage 
 Example : 10 counties 
 f) Target demographic representation 
 Example:  Balanced across gender and five age groups. 
 
 The Africa Next Voices project targeted approximately 3,000 hours across five languages, with different targets per language. 
 
 g) Create a simple target sheet 
 
 
 
 
 
 Metric 
 
 
 Target 
 
 
 
 
 Speakers 
 
 
 1,000 
 
 
 
 
 Total hours 
 
 
 500 
 
 
 
 
 Scripted 
 
 
 125 hrs 
 
 
 
 
 Unscripted 
 
 
 375 hrs 
 
 
 
 
 Regions 
 
 
 10 
 
 
 
 
 Dialects 
 
 
 4 
 
 
 
 
 Female 
 
 
 50% 
 
 
 
 
 Male 
 
 
 50% 
 
 
 
 
 Age groups 
 
 
 5 
 
 
 
 
 
 Your numbers will depend on your project. The table is a planning tool, not a universal standard . 
 
 3. Define Your Language 
 Do not simply write: 
 “We are collecting Language X.” 
 Ask: 
 
 
 Which variety? 
 
 
 Which dialects? 
 
 
 Which geographic areas? 
 
 
 Which communities? 
 
 
 Is the language internally diverse? 
 
 
 Are some varieties more widely used? 
 
 
 Are some varieties endangered? 
 
 
 Which varieties are appropriate for the intended use? 
 
 
 
 Example : The AFN project explicitly considered dialect variation in languages including Kalenjin, Maasai, Somali, Dholuo and Kikuyu. 
 
 Create a language profile 
 Record: 
 
 
 Language: 
 
 
 Language family: 
 
 
 Country/countries: 
 
 
 Main regions: 
 
 
 Dialect groups: 
 
 
 Estimated speaker distribution: 
 
 
 Existing digital resources: 
 
 
 Existing speech datasets: 
 
 
 Native-speaker experts: 
 
 
 Relevant institutions: 
 
 
 
 4. Define Your Dialect Strategy 
 This is one of the most important steps. 
 A dataset can contain thousands of hours and still be poorly representative if most speakers come from one location or dialect. 
 Create a dialect matrix: 
 
 
 
 
 
 Dialect 
 
 
 Geography 
 
 
 Target speakers 
 
 
 Target hours 
 
 
 
 
 Dialect A 
 
 
 Region 1 
 
 
 200 
 
 
 100 
 
 
 
 
 Dialect B 
 
 
 Region 2 
 
 
 200 
 
 
 100 
 
 
 
 
 Dialect C 
 
 
 Region 3 
 
 
 200 
 
 
 100 
 
 
 
 
 Dialect D 
 
 
 Region 4 
 
 
 200 
 
 
 100 
 
 
 
 
 
 
 The Africa Next Voices project used explicit dialect targets and geographic recruitment rather than treating each language as homogeneous.