Different linguistic modalities (speech or sign) offer different levels at which signals can iconically represent the world. One hypothesis argues that this iconicity has an effect on how linguistic structure emerges. However, exactly how and why these effects might come about is in need of empirical investigation. In this contribution, we present a signal creation experiment in which both the signalling space and the meaning space are manipulated so that different levels and types of iconicity are available between the signals and meanings. Signals are produced using an infrared sensor that detects the hand position of participants to generate auditory feedback. We find evidence that iconicity may be maladaptive for the discrimination of created signals. Further, we implemented Hidden Markov Models to characterise the structure within signals, which was also used to inform a metric for iconicity

Previous research has shown that repeated interactions cancause iconicity in signals to reduce. However, data from sev-eral recent studies has shown the opposite trend: an increase iniconicity as the result of repeated interactions. Here, we dis-cuss whether signals may become less or more iconic as a re-sult of the modality used to produce them. We review severalrecent experimental results before presenting new data frommulti-modal signals, where visual input creates audio feed-back. Our results show that the growth in iconicity presentin the audio information may come at a cost to iconicity inthe visual information. Our results have implications for howwe think about and measure iconicity in artificial signallingexperiments. Further, we discuss how iconicity in real worldspeech may stem from auditory, kinetic or visual information,but iconicity in these different modalities may conflict