“Time Averaging” has the effect of smoothing out the refresh rate Acoustic Image by averaging the
currently visible Acoustic Image “frame” together with those frames preceding it. Moving the slider to
the left increases the effect of time averaging. This makes it easier to observe the changes in SPL in a
scene, but also introduces some delay. Moving the slider to the right will show all the instantaneous
sources and reflections captured by the camera but the visual cacophony can be overwhelming.
The “Stitch Depth” slider changes the distance at which the camera images are properly stitched
together in the Video Window. When the slider is moved all the way to the right, the cameras are
stitching together at 20’ to infinity. When recording in a tight space, like the inside of a car, the slider will
need to be adjusted until the video cameras edges line-up with each other at the distance of the
suspected noise source.
The “Stitch Depth” slider must be set before making a recording to
ensure the accuracy of the Audio Image overlay. This cannot be altered once a recording is
made.
4.3 Realtime Display
4.3.1 Starting the Camera
1. Connect your Audio Camera to the laptop running FINDr with the included USB 3.0 cable.
2. Connect the included power supply to your Audio camera and tu
rn the power switch to the “on”
position.
3. Open the FINDr software. The FINDr icon should be in the system tray on the bottom of your Windows
10 home screen.
4. Select the SPL range for your recording with the Camera Gain button, located in the Camera Controls
box in the right-hand window of the FINDr software.
5.
Click on the “Start Camera” button in the “Camera Controls” dialog box. The Audio Camera will take a
few moments to start up so please be patient.
4.3.2 Realtime Mode
This mode is active when the camera is started in FINDr; the stitched video image and overlaid color gradient
Acoustic Image will be visible in the Video Window. Use of the Control Panel functions allow for the Acoustic
Image to be tweaked and can help to focus on frequencies of interest. Realtime mode can be used on its own
to detect and analyze sound, but also serves to refine Acoustic Image settings in preparation for a recorded
session.
A description of useful functions for Realtime Mode is in the sections which follow.
4.3.2.1 Beamforming with Virtual Microphones
While in Mercator projection, a double left click in the Video Window places a red dot in the Acoustic Image.
The dot represents a virtual microphone with steered isolation of up to 24 dB, approximated using
beamforming. Multiple virtual mics can be placed in the Video/Acoustic Image. Click and drag on the red dot to
alter the position of a previously placed virtual microphone. Right click to remove the last virtual microphone
placed. All virtual microphones will be combined into one track while listening in Realtime Mode.
The Beamforming tab in the Control Panel (
) houses the controls and display for the Virtual Microphone
features.
The contents of the Beamforming tab are as follows:
