Grozier Technical Systems, Inc.

ESTABLISHING SOUND LIMIT VALUES
Shorter-term Sound Limits for Proactive Control

The Sound Level Regulation Limits have already been set, So how do you prevent them from being exceeded?
Grozier systems are ultimately used to qualify concert sound levels to determine if the local noise regulation limit has been exceeded. But this after-the-fact information is not really much proactive use to a music facility. Therefore, Grozier systems are designed to be effective as a concert proceeds. Parameters are presented to the management and sound engineer that encourage this proactive capability. The goal, of course, is to never have an excessively loud concert.

Since the needs of each concert venue are different, so is its Grozier system. The need is to meet the local noise regulation and the unique positioning of the music venue relative to the nearby community. But some general features are common throughout most Grozier systems. Just one is these is the ability to set limits on the Leq 1 sec sound levels. If limits are exceeded, then a simple "traffic light", located on the screen in front of the sound engineer, changes color. In the example given below, the 1 second Leq sound level is yellow.

Just how Leq 1 second is is related to any metric used in a noise regulation, can be found by clicking here. It can be seen that even the Leq 1-second can be indicative of the Leq 1-minute and in turn to the Leq 10 minute. Using the noise regulation limit and the data presented here, this 1-second limit can easily be established. Similarly the Leq 1 minute limit can be established.

This has been done in the example above, and the traffic lights for these two "Advisory Information" limits are seen in the upper row.

The "City Regulation" limits are seen in the row below.

As a concert proceeds that "traffic light" data and the sound level data is stored so that a graphical plot can be generated, such as in the example of the Beach Boys above. The data from this type of plot is also used in prediction algorithms that show whether the concert will exceed the sound regulation limits before the concert's end.