# Machine Assisted Analysis of Vowel Length Contrasts in Wolof

## TL;DR

This paper demonstrates an automated approach to analyze vowel length contrasts in Wolof, revealing how speech style and dialect influence phonetic variation using over 20,000 tokens.

## Contribution

It introduces new automatic features for evaluating vowel length contrast and applies them to Wolof, an under-resourced language, across different speech styles and dialects.

## Key findings

- Contrast weaker in semi-spontaneous speech
- Contrast weaker in non-standard dialects
- Features effectively distinguish degrees of vowel length contrast

## Abstract

Growing digital archives and improving algorithms for automatic analysis of text and speech create new research opportunities for fundamental research in phonetics. Such empirical approaches allow statistical evaluation of a much larger set of hypothesis about phonetic variation and its conditioning factors (among them geographical / dialectal variants). This paper illustrates this vision and proposes to challenge automatic methods for the analysis of a not easily observable phenomenon: vowel length contrast. We focus on Wolof, an under-resourced language from Sub-Saharan Africa. In particular, we propose multiple features to make a fine evaluation of the degree of length contrast under different factors such as: read vs semi spontaneous speech ; standard vs dialectal Wolof. Our measures made fully automatically on more than 20k vowel tokens show that our proposed features can highlight different degrees of contrast for each vowel considered. We notably show that contrast is weaker in semi-spontaneous speech and in a non standard semi-spontaneous dialect.