Ambient Noise oversampling

[nleo575]

During testing the ambient noise plugin was recording much more data than the sensor was set to record. This problem persisted even after turning on the enforce all setting.

For example, the sensor was recording what appears to be 60 samples per second for a 30 second window, instead of 1 sample per second for a 30 second second window. The records look almost to be duplicates, except that the _id is different. This did not happen every sampling cycle, but looking at our data averaged over 1 minute intervals, it raised the average sampling rate from 30 records per five minutes for the iOS devices, to as much as 440 samples per every five minutes.

We experienced some variation on the oversampling frequency on all (4 of 4) Android devices during a three week test.