its completely impossible to sleep there at any time of day due to the excessive noise
Yikes! Sorry to hear that! But first, please tell us where in Spain is this Calle Fuencarrall?? Was it in Cuenca, Salamanca, Barcelona, Toro, Alcalá de Guadaira, Madrid, Finnesterre, or some other place?
What time of the day was this? 1pm, 6pm, 8am, 4am, 9pm? Most streets are noisier during the day than night .
What kind of noise did you experience? Was it a festival, traffic, discos, "botellónes", marching bands, 4 a.m. garbage pickup, alien invasions, or other??
And did you have an inside room or an outside room facing the street? Single, double, or triple pane windows? Were you staying at a friend's house, hotel, or hostel? Was there some special event taking place?
Saludos, MadridMan