Abstract
This chapter surveys research suggesting that languages adapt to external pressures, focusing most heavily on the possibility that some features of sound systems are adaptive. It details a general methodological approach used to explore adaptive effects in this domain, which proceeds by first generating hypotheses from findings in fields like laryngology and orthodontics. These hypotheses are then tested with correlations between non-linguistic data and typological data and potentially supported with other sorts of data including analyses of actual speech and biomechanical modelling. This general method is illustrated here via a discussion of two relevant hypotheses in the literature, one related to labiodental sounds and one related to vocal cord vibration. I rely on several recent papers on these topics, which have advanced this work methodologically, while also offering some illustrative data. Finally, I present some concluding remarks.