1974] 
W ussow et al. — Sounds and Motions of Insects 
211 
parameters noted : i ) distance from the microphone to the subect, 
and 2) the average temperature of air between subject and micro- 
phone. Then we played the recorded sequence on a compatible 
video-tape reproducer (VTR.!) which was linked by a multichannel 
synchronizing circuit (SWITCHER) to another video-recorder 
(VTR 2 ) which preferably used at least one-inch tape. Figure l 
diagrams the set-up schematically. The audio circuit of the VTR a 
was linked also to the input of an oscilloscope (CRO), the screen 
(CRT) of which has an image persistence on the order of micro- 
seconds (Pi i phosphor coating). A video-camera (CAM) focused 
on the CRT image which was positioned so that it would not mask 
the image of the subject in the superposition. If the trace was to be 
positioned along the bottom of the frame, the horizontal sweep of 
the CRO was set at io msec/cm so that a single sweep of 12.5 cm 
will encompass at least eight video fields (q. v., sect. 7 & 8, Analysis 
and Fig. 1 for further explanation and an alternative method). We 
also masked the negative potentials with opaque tape. The video- 
camera is connected with the VTR 2 by the vertical interval switcher 
and the CRT screen is shielded by an improvised hood from the 
room lights. The results of superposition are simultaneously video- 
monitored. 3 
The resulting video-tape, minus all the inactive time, can be played 
on a VTR which has stop-action and single-field forwarding capabil- 
ity (or the tape can be moved forward by hand). The audio signal 
can still be heard as well as seen as an oscillo-trace when the VTR 
is running at normal speed. At low speed the audio circuit auto- 
matically turns off and, although an adustment can be made in the 
machine’s circuitry to enable the sound to be heard, with the oscillo- 
graphic trace this is neither necessary nor desirable. With the VTR 
stopped on a single field, we marked with a wax crayon the positions 
of the moving parts on the projection screen of the monitor and made 
measurements of the angle changes with a protractor ( a better method 
will be outlined later in section 9, Analysis). 
Equipment used: “Quiet Room” (Suttle, Inc., Chicago), Audiometric 
Room, double-walled (Industrial Acoustics, New York), Sony EV-310 25 mm 
videocorder, Scotch Brand MT 20568 video-tape, General Electric model 
4TE33D1 TV camera with a Soligor 10 cm, lens, Sony AVC 3200 TV 
camera with Angenieux 7.5 cm lens with a +1 diopter auxiliary lens, 
AKG shotgun microphone model D900, vertical interval switcher-sync 
generator with sync lock capability (Shintron 360), Tektronix 502A os- 
cilloscope with Pll phosphor, Panasonic video-monitors (3-inch), one 50W 
electric spot bulb. 
