Environmental noise monitoring system

1. A system for unattended noise monitoring, comprising:

an analog section for detecting noise and for simultaneously weighting the noise through A- and C-frequency filters in accordance with national and international noise measurement standards;

a processing section for converting the detected and weighted noise to one or more Leq data;

a communications interface for remote control of, and data communication with, the processing section; and

an analysis unit for displaying, processing and detecting events in the Leq data.

2. A system of claim 1 , the processing section comprising firmware to control the noise monitoring unit.

3. A system of claim 1 , the analog section further comprising logarithmic amplifiers for converting the detected and weighted noise to a range suitable for analog to digital conversion.

4. A system of claim 3 , the processing section further comprising an analog to digital converter.

5. A system of claim 1 , further comprising a display for displaying data from the processing section, the display being in communication with the processor.

6. A system of claim 1 , further comprising a keypad for inputting data to the processing section, the keypad being in communication with the processor.

7. A system of claim 1 , the processing section generating one or more of maximum, minimum, 1/10th percentile, 1/50th percentile, 1/90th percentile Leq data.

8. A system of claim 1 , the processing section comprising memory for storing tip to about two weeks of the data.

9. A system of claim 1 , further comprising a portable power supply for powering the sections.

10. A system of claim 9 , the power supply comprising a rechargeable battery.

11. A system of claim 9 , the power supply comprising solar power converters.

12. A system of claim 1 , wherein the data comprises one-second equivalent averages of the noise.

13. A method for environmental noise level monitoring, comprising the steps of:

detecting and converting sound waves into first and second identical analog electrical signals;

filtering the first signal for A-weighted information and generating a third signal representing an envelope of the filtered A-weighted signal;

filtering the second signal for C-weighted information and generating a fourth signal representing an envelope of the C-weighted filtered signal;

compressing the third and fourth signals using logarithmic amplifiers into a range of logarithmic signals suitable for digitization;

converting the logarithmic signals into digital data using an analog-to-digital converter;

calculating 1-second Leq values for the digital data;

calculating hourly averages of the Leq values;

calculating one or more of maximum, minimum, 1/10th percentile, 1/50th percentile, 1/90th percentile Leq and time-weighted data; and

storing the Leq and statistical data in non-volatile memory.

14. A method of claim 13 , further comprising

transferring stored data from the non-volatile memory to a noise analysis unit;

displaying the transferred data in graphical form at the noise analysis unit;

processing the transferred data to produce statistical information; and

classifying noise events in the transferred data.

15. A software product having instructions, wherein the instructions, when executed by a computer, provide for environmental noise level analysis, comprising:

Instructions for downloading Leq and statistical environmental noise data from a system for unattended noise monitoring;

Instructions for storing the Leq and statistical environmental noise data on a PC as a text file;

Instructions for displaying the Leq and statistical environmental noise data; and

Instructions for isolating sound level events over a first user-defined threshold;

Instructions for isolating a minimum time over a second user-defined threshold level, and

Instructions for isolating a minimum LAeq to LCeq ratio.

16. The software product of claim 15 , wherein the instructions for displaying the Leq and statistical data comprise:

instructions for graphically displaying 1-second Leq sound data over a user-selected time period, and

instructions for creating tables showing hourly and daily summaries of the 1-second Leq data.

17. The software product of claim 16 , farther comprising instructions for zooming in to a user-selected time period in response to a user request.

18. The software product of claim 15 wherein the instructions for displaying the Leq and statistical data comprise instructions for graphically displaying 1-second, 10-second, 1-minute, 1-hour and 1-day averaging times for a user-selected time period.

19. The software product of claim 15 wherein the instructions for displaying the Leq and statistical data comprise instructions for displaying start time, end time, duration, Lmin, L 90 , L 50 , L 10 , Lmax, LAeq and LCeq for a user-selected time period.