The first detailed study of the bioacoustics of Isophya fatrensis has been published. This species was described as recently as 2007 and is endemic to the Slovakian western Carpathian mountains. The song and male-female acoustic duetting is a bit similar to Isophya harzi, but the authors present some clear differences, thus confirming the specific status of this species.
Iorgu, I.S., A. Krištín, G. Szövényi, P. Kaňuch, B. Jarčuška, T. C. Sahlean, E.I. Iorgu & K.M. Orci 2017. Distinctive male–female acoustic duetting supports the specific status of Isophya fatrensis, a West-Carpathian endemic bush-cricket (Insecta: Orthoptera: Tettigoniidae: Phaneropterinae). Bioacoustics, DOI: 10.1080/09524622.2016.1272005
Oscillogram of the male calling song of Isophya fatrensis and other Isophya species of the Carpathians.