SILVERDALE — From 8 a.m. to 5:30 p.m.residents surrounding Naval Base Kitsap (NBK) Bangor and Keyport locations will hear sounds, including voice announcements, sirens and various tones and static noise produced from several loudspeaker towers. The testing will occur at intervals of about one to one-and-a-half minutes within a 10-minute period. Volumes will vary between low and high but the duration of the higher volume sounds will be shorter than the lower sounds. The testing is being done to ensure recent upgrades to the installation’s mass warning and notification system, known as Giant Voice, are functioning properly while meeting Federal Emergency Management Agency and Navy standards for emergency notifications. These upgrades enhance the Navy’s ability to immediately communicate important information during emergencies to Navy personnel, including military members and their families, and Navy civilian employees and contractors living or working on Navy property.Upgrades to NBK Bremerton’s system is scheduled to begin in August and finish in November 2018.The Navy aims to reduce impacts of this system to neighboring communities,while maintaining the ability to meet its mass notification requirements. The system is used to play the national anthem and does routine weekly system testing.