Helmholtz resonator with two resonance frequencies by coupling with a mechanical resonator Hoppen, Hannah Langfeldt, Felix Gleine, Wolfgang Estorff, Otto von 2023 - TUHH Open Research
Impact of surface roughness on acoustic resonators made of closed-cell lightweight foams Hoppen, Hannah Suresh, Hrishikesh Langfeldt, Felix Gleine, Wolfgang Estorff, Otto von 2021 - TUHH Open Research
Aircraft side wall with improved low-frequency sound insulation using a lining panel with Helmholtz resonators Hoppen, Hannah Langfeldt, Felix Gleine, Wolfgang Estorff, Otto von 2019 - TUHH Open Research