The Summer Island Noise Monitoring Project
(updated December 22, 2024)
Background:
Summer Island is a beautiful spot located about 20 miles South of St Augustine in Florida. It is a subdivision of homes nestled between the intercoastal waterway to the West and the ocean to the East. Access is from State Route A1A, the coastal road that runs from St Augustine South to Daytona Beach.
For most of the time, Summer Island is peaceful and quiet. Depending on the weather and time of year, you can hear the ocean, sometimes the frogs, and sometimes the wind, especially when hurricanes pass nearby. There is some traffic noise from Route A1A but traffic is usually light, depending on the time of year.
But sadly, the peace is sometimes shattered by inconsiderate people and their noisy toys. Summer Island Drive is the access road to Helen Mellon Schmidt State Park which also provides access to Fort Matanzas Federal Park. Many trucks and kayaks pass quietly in and out during the day. Not a problem. But there are an increasing number of trucks sporting switchable by-pass mufflers (a meagre $400 upgrade). As they leave up the incline to the bridge, some open up their muffler and give it full gas so everyone in the park and subdivision can hear them leaving. And not just people vising the park. In the subdivision we now have a couple of trucks (a white one and a pale gray/silver one) with similarly modified mufflers, the sound of which is annoying a number of the residents here.
I have worked in the sound / hearing field for over 40 years. To demonstrate that there is a problem here in a scientific manner you need to collect data. One part of the company I work for, Turner Scientific, deals with sound monitoring in laboratories and animal facilities. The system they sell can be seen by clicking here. They graciously set me up with one of their “Sensory Sentinel” recording systems which we mounted on the house to measure sound levels outside.
Sensory Sentinel Noise Measurements
The Sensory Sentinel system uses a high-quality ¼”, calibrated microphone to detect ambient sounds. Sound levels measured in dB SPL are logged at 1 second intervals, 24 hours per day (over 86,000 measurements per day). Measurements are streamed to the cloud, and are available for any authorized user to work with.
The distance of the measurement from vehicles is 98 feet for the outgoing side of Summer Island Drive and 260 feet from the near side of Highway A1A, as shown in the Google Earth measurements below.
An example of the measurements is shown below. The blue plot shows all the measurements over the entire day. You can see that it is quiet at night, when traffic is sparse, and increases during the day, especially in the afternoon. For most vehicles the noise is dominated by tire noise. The higher noise episodes correspond to cars, trucks or motorcycles with inadequate exhaust mufflers.
There is one vehicle on the record that stands out well above the rest. The sound was made by “the white truck from June Lane”. The sound is about 6 dB higher than all other vehicles. As the dB scale is logarithmic, a 6 dB increase makes it twice as loud as all other vehicles for that day.
More detail of the record is shown below.
While accelerating out of Summer Island Drive onto A1A a peak sound level of 92.7 dB SPL was recorded. As sound decreases with distance by an inverse square law, we can calculate sound levels at different distances, increasing by 6 dB for each halving of the distance.
Distance (ft) Level (dB SPL)
262 92.7
131 98.7
65.5 104.7
32.8 110.7
This shows that even at 30' away the truck is over 110 dB SPL which is highly illegal.
The truck involved was confirmed from video + audio recordings from the house security system, which covers July Lane, the entrance gate / park gate area, Summer Island Drive and A1A. The soundtrack confirmed that the noise was generated by the specific vehicle that was visually identified.
Although we had drafted a detailed complaint to file with the St. Johns Sheriff Office, after consulting with other affected homeowners we elected to first contact the homeowner/parent of the driver directly. And to give credit where it is due, the driver did take notice, with the noise from the truck now reduced considerably. In the weeks since, measured noise from the this truck has stayed below 90 dB SPL, a level we regard as critical. If it stays that way, there will be no need to pursue the problem further.
For vehicles using the park we need to install a high-resolution camera to read plates so we can provide that information along with the sound record to the St Johns County Sheriffs Office. However, there are apparently plans by SJSO to install plate-reader cameras at the park gate, so noise level and exact time may be sufficient to identify illegal vehicles.
We appreciate that there are some welcome noise sources (the sound of the surf) and others that are less welcome, many of which are beyond our control. Nevertheless, we can certainly spotlight “egregious cases” and work to reduce their influence. Below is the sound of a typical day here on Summer Island. Most of the spikes are from vehicles passing along A1A, all below the critical 90 dB SPL mark. The baseline rising during the day was "surf noise" of the sea. So, wishing you all a similar, or lower noise level in your location and a Happy, Peaceful Christmas
