10 
a 
E 
o 
~ 
v 
oO 
7 
> 
uv 
s 
o 100 
od 
N 
© 
2 
vv 
2 
p) 
v 
| 90 
= 
=) 
a 
i 
> 
fo) 
80 
10 20 30 40 50 60 70 80 90 100 
FREQUENCY— KHz 
Figure 7,--Frequency response of ultrasonic speaker with a polarization voltage of 220 volts 
d.c, and a 100-volt p-p input, 
W2 
105 
100 
95 
90 
85 
80 
—l100KHz2 
OUTPUT— db(O db re 2xlO~*dynes /cm2) 
ifs) 
70 
ie) 10 20 30 40 50 60 70 80 90 
Angle of Transducer in Relation to the Microphone—Degrees 
Figure 8,--Directional characteristics of ultrasonic speaker at frequencies of 10, 22, 45, and 
100 KHz, 
