Here is a popular press piece (link here) on the first documented sound production in lionfish. The original paper well qualifies that these data are just preliminary, but very interesting what role this sound production may play. Here is a paragraph from the article with some speculation:
Sound is a critical component of fish social behaviour and sound production has been well documented throughout the Scorpaenidae family (Kasumyan, 2008). Little is known about invasive P. volitans or P. miles social behaviour, but there is evidence to suggest they may display similar behaviours as the zebra lionfish Dendrochirus zebra (Cuvier 1829). Rizzari & Lönnstedt (2014) found that D. zebra participate in cooperative hunting and Lönnstedt &McCormick (2013) suggest this also occurs in P. volitans and P. miles.Moyer & Zaiser (1981) report a variety of additional social behaviours in D. zebra including social organization and aggregation, which they attributed in part to size (i.e. evidence of dominant behaviours). Jud & Layman (2012) suggest Pterois spp. may be displaying similar social organization behaviours in the Atlantic Ocean.Not limited to Scorpaenids, Stout (1975) reported larger satinfin shiner Cyprinella analostana Girard 1859 produce a ‘rapid series of knocks’ as an aggressive and dominant behaviour. It is unknown whether or, if so, how sound plays a role in the social behaviour of Pterois spp. The rapid increase in the rate and frequency, the change in pulse pattern of the repetitive pulse calls and the existence of the low frequency hum recorded when multiple fishes were in the tank, especially one noticeably larger fish, suggests that it may. Further research is needed to identify and describe size, sex, context and behaviour specific vocalizations.