This 2 August 2014 video from Germany shows a Chorthippus dorsatus grasshopper calling.
Translated from Nature Today in the Netherlands:
10 AUGUST 2018 – On 1 August, a male Chorthippus dorsatus grasshopper was observed in nature reserve Lonnekerberg. The last observation of this very rare grasshopper [in the Netherlands] dates from 26 years ago at Denekamp. Further research will have to show whether there is a population, or whether it concerns a vagrant animal from one of the German populations.