Table 3: Summary of the literature studies related to environment recognition based on the ANN method. The number of environments analyzed, the average accuracy and the accuracy-related to each environment are reported.

Study (Refs.)	# Environments (per study)	Average Accuracy (per study)	Accuracy Emergency Vehicles	Accuracy Sneezing	Accuracy Dogs	Accuracy Clock Ticking	Accuracy Baby Crying	Accuracy Crowing Rooster	Accuracy Raining	Accuracy Sea Waves	Accuracy Fire Crackling	Accuracy Helicopter	Accuracy Chainsaw	Accuracy Street
[56]	1	96.70%	96.70%	–	–	–	–	–	–	–	–	–	–	–
[58]	10	74.50%	–	74.50%	74.50%	74.50%	74.50%	74.50%	74.50%	74.50%	74.50%	74.50%	74.50%	–
[60]	2	58.26%	93.22%	–	–	–	–	–	–	–	–	–	–	23.30%
[62]	5	88.76%	–	–	–	–	88.76%	–	–	–	–	–	–	–
[61]	2	93.73%	–	–	–	–	98.22%	–	–	–	–	–	–	–
[59]	11	80.02%	80.02%	–	80.02%	–	–	–	80.02%	80.02%	–	–	–