However, if your dog shows one or several of these signs in response to a noise, please seek help from your veterinarian. (vetmed.illinois.edu)
Fear of noises is a normal adaptive response to a real threat, resulting in behavioral and physiological survival responses that drive the dog to seek shelter or otherwise avoid the imminent danger.4 However, when the fearful response to noise is persistent, exaggerated in intensity and duration and results in what appears to be an anxiety attack, this is not normal. (zoetisus.com)
[5] Pedersen E, Bakker R, Bouma J, van den Berg F. Response to noise from modern wind farms in the Netherlands. (na-paw.org)