# Stability and Fluctuations in a Simple Model of Phonetic Category Change

## TL;DR

This paper presents a simple exemplar model demonstrating that phonemes in spoken language are stable over time, with boundaries fluctuating, contrasting with more complex models where phonemes can go extinct.

## Contribution

The study introduces a basic exemplar model showing phoneme stability and boundary fluctuations, providing a foundation for future models with phoneme extinction or emergence.

## Key findings

- Phonemes do not go extinct once established.
- Boundaries between phonemes fluctuate over time.
- The model quantifies phonetic boundary fluctuations.

## Abstract

In spoken languages, speakers divide up the space of phonetic possibilities into different regions, corresponding to different phonemes. We consider a simple exemplar model of how this division of phonetic space varies over time among a population of language users. In the particular model we consider, we show that, once the system is initialized with a given set of phonemes, that phonemes do not become extinct: all phonemes will be maintained in the system for all time. This is in contrast to what is observed in more complex models. Furthermore, we show that the boundaries between phonemes fluctuate and we quantitatively study the fluctuations in a simple instance of our model. These results prepare the ground for more sophisticated models in which some phonemes go extinct or new phonemes emerge through other processes.