The articles one this page are all recommended by Carol Millman B.Sc, AHT, CPDT-KA, CTDI of WagTheDog.ca
Thank you, Carol!
This study shows that unexpected loud and unpredictable / irregulary occurring sounds have a strong correlation to anxiety and cortisol in dogs
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8606548/
This article shows that noise sensitivity is one of the most common causes of anxiety in dogs and that anxious dogs are more aggressive
https://www.sciencedirect.com/science/article/pii/S1558787816300569
Here is a good article on the topic too
And dogs raised in cities are much more fearful of noises than dogs raised in rural environments, even though they SHOULD be more accustomed to them.
https://newatlas.com/biology/study-urban-dogs-more-fearful-rural-dogs/
Carol Millman B.Sc, AHT, CPDT-KA, CTDI