Dataset for the paper: Cabrera, D; Lu, S.; Holmes, J; Yadav, M. Sound reflections in Indian stepwells: Modelling acoustically retroreflective architecture. Acoustics 2022. This dataset represents the acoustic response (in the form of impulse responses) of example Indian stepwells and associated data. The purpose of this was to investigate the acoustic phenomenon of retroreflection from the numerous concave trihedral corners of the stepwells. Two example stepwells were simulated using finite-difference time-domain (FDTD) acoustic simulation: Lahan Vav and Panna Meena ka Kund. Note that Lahan Vav has the alternative name of Vasantgadh Stepped Pond, which is used to name some files. Geometric models used for the simulations are in Rhino (.3dm) format. Result data is in Matlab (.mat) format. Details of the simulation are provided in the article. Basic simulations used the following settings: src func. Gausian pulse. src type soft source [Botts] pml width 10 [Chern] Sampling rate 60000 Hz Lahan Vav (Vasantgadh) x y z volume 18.78 12.64 8.82 2.0932e+03 m^3 i j k total nodes(not inc. PML) 893 1275 890 2.14808175e+09 dx 9 mm rec spaced 4 x dx 151206 Panna Meena ka Kund x y z volume 12.58 18.12 10.05 2.2905e+03 m^3 i j k total nodes(not inc. PML) 1269 1827 1014 2.350921482e+09 dx 9 mm receiver grid 4 x dx 145326 Folder names: LAHAN VAV FDTD: This folder contains Rhino models and Matlab results for FDTD simulations of Lahan Vav (also known as Vasantgadh). _80: simulations done with trihedral angles of 80 degrees (instead of 90 degrees). This was done to evaluate the effect of geometric error. _85: simulations done with trihedral angles of 85 degrees (instead of 90 degrees). This was done to evaluate the effect of geometric error. _90: main simulations: includes output for each position across the horizontal receiver array, as well as for just the position closest to the source. _95: simulations done with trihedral angles of 95 degrees (instead of 90 degrees). This was done to evaluate the effect of geometric error. _100: simulations done with trihedral angles of 100 degrees (instead of 90 degrees). This was done to evaluate the effect of geometric error. _anechoic: simulations done with a perfectly matched layer and no reflective surfaces This was done to enable the direct sound to be subtracted from the impulse responses. _flat: simulations done with simplified (flat) stepwell surfaces. This was done to compare simple surfaces with potentially retroreflective surfaces. _individual_receivers: simulations done for 0.5 s duration for receivers distributed at various positions in and on the stepwell. This was done to examine retroreflection in the context of the stepwell’s reverberation. Two source positions were used (P1 and P6). Corresponding anechoic results are included in this folder. PANNA MEENA FDTD: This folder contains Rhino models and Matlab results for FDTD simulations of Panna Meena ka Kund. Note that only a partial model was used (because of computational limitations), hence the use of ‘half’ on the names in this folder (note that the model is actually less than half of the real stepwell volume). _half_80: simulations done with trihedral angles of 80 degrees (instead of 90 degrees). This was done to evaluate the effect of geometric error. _half_85: simulations done with trihedral angles of 85 degrees (instead of 90 degrees). This was done to evaluate the effect of geometric error. _half_875: simulations done with trihedral angles of 875 degrees (instead of 90 degrees). This was done to evaluate the effect of geometric error. _half: main simulations: includes output for each position across the horizontal receiver array, as well as for just the position closest to the source. _half_925: simulations done with trihedral angles of 925 degrees (instead of 90 degrees). This was done to evaluate the effect of geometric error. _half_95: simulations done with trihedral angles of 95 degrees (instead of 90 degrees). This was done to evaluate the effect of geometric error. _half_100: simulations done with trihedral angles of 100 degrees (instead of 90 degrees). This was done to evaluate the effect of geometric error. _anechoic: simulations done with a perfectly matched layer and no reflective surfaces This was done to enable the direct sound to be subtracted from the impulse responses. _half_flat: simulations done with simplified (flat) stepwell surfaces. This was done to compare simple surfaces with potentially retroreflective surfaces. _temp_inv: simulation using a 0.5 degC/m vertical temperature gradient. VISIBLE REFLECTORS AND SIMPLIFIED MODELS: This folder contains data on the visible reflectors in stepwells, in Matlab format. PannaMeena_and_Lahan_top_positions: has distances and angles to visible trihedral corners corresponding to the positions used for FDTD simulations. 1 st column=distance, 2nd column=incident angle, 3rd column=incident angle for short edge, 4th column=incident angle for long edge, 5th column=if big. PannaMeena_lower_level_positions: has distances and angles to visible trihedral corners at lower positions. 1st column=distance, 2nd column=incident angle, 3rd column=if big. H4=4m below top (mid loggia), H8=8.2m below top (main loggia). Simplified_model_data: has distances and angles to visible trihedral corners of 10 simplified models of stepwells. Each row represents a visible retroreflector. The first column is the distance, the second column is the incidence angle, and the third column indicates the type of the reflector (0=small, 1=large) The folder also contains scripts that analyse the data with a simplified acoustic model. ChandBaoriLevelsCalculator calculates the retroreflected sound over a range of heights in a simplified model of Chand Baori.