As part of the monitoring of impulsive sounds, event monitoring includes information on the sources of impulsive sound associated with seismic surveys, explosions, pile driving and sonars operating at the monitored frequencies as well as scaring devices. In case of explosions, monitoring is based on information on security and defence activities related with detonating explosives on seven military training grounds (P-9, P-10, P-20, P-21, P-32, P-33, P-34). Thresholds have been set at EU level above which the influence of impulsive sounds is considered harmful and for which sounds should be recorded.

As part of the monitoring of impulsive sounds, event monitoring includes information on the sources of impulsive sound associated with seismic surveys, explosions, pile driving and sonars operating at the monitored frequencies as well as scaring devices. In case of explosions, monitoring is based on information on security and defence activities related with detonating explosives on seven military training grounds (P-9, P-10, P-20, P-21, P-32, P-33, P-34). Thresholds have been set at EU level above which the influence of impulsive sounds is considered harmful and for which sounds should be recorded.

Monitoring of underwater sound in the scope of anthropogenic continuous low-frequency sound is conducted in Polish Marine Areas. In the scope of continuous sound, the distribution of individual measuring devices was designed specifically to obtain continuous sound characteristics in each assessment unit: Bornholm Basin, eastern Gotland Basin, Gdansk Basin and Gdańsk Basin Polish Coastal waters. Recordings of sound pressure level (SPL) of continuous low-frequency sound are performed for 1/3 octave bands of 63, 125 and 2000 Hz, equivalent to 1 μPa, according to guidelines (HELCOM Guidelines for monitoring continuous noise).

Monitoring of underwater sound in the scope of anthropogenic continuous low-frequency sound is conducted in Polish Marine Areas. In the scope of continuous sound, the distribution of individual measuring devices was designed specifically to obtain continuous sound characteristics in each assessment unit: Bornholm Basin, eastern Gotland Basin, Gdansk Basin and Gdańsk Basin Polish Coastal waters. Recordings of sound pressure level (SPL) of continuous low-frequency sound are performed for 1/3 octave bands of 63, 125 and 2000 Hz, equivalent to 1 μPa, according to guidelines (HELCOM Guidelines for monitoring continuous noise).