Recently we have obtained evidence that shows that the dolphins communicate most of their information in the band of frequencies extending from about 8 kilocycles to 20 kilocycles by means of whistles and sonic clicks.[11] However, as shown by Schevill and Lawrence, they can hear sounds at least to 120 kilocycles[12] and as shown by Kellogg can produce sounds at least to 170 kilocycles.[10] We have recently been investigating the higher frequency bands in these animals and have reliable evidence that they can hear at least to 200 kilocycles and can produce sounds to at least 200 kilocycles.[7][13] With the proper electronic equipment one can listen to the nearer portions of the upper band and quickly determine that they can transmit in these bands without the necessity of transmitting in the (lower frequency) communication band. The high frequency information is broadcast in a narrow beam off the front of the beak as was first detected by Kenneth Norris.[14] In these bands we find that they can produce musical tones or individual clickings or hissing-like noises. Recently we have found that an emotionally upset animal threatens other animals and humans by productions of very large amounts of energy both in the sonic communication band and in the ultrasonic bands. Recently we have had the opportunity of working with an old bull of 450 pounds weight who is so old his teeth have been ground down flat. In terms of his skeleton, he is the most massive animal we have ever seen. When he is irritated, his “barks” have sizable amounts of energy from about 0.5 to at least 300 kilocycles. He is also capable of transmitting in bands between 100 to 300 kilocycles without transmitting anything in the band from 8 kilocycles to 20 kilocycles in a narrow beam straight ahead of his body. When he is upset by the activities of a younger male, they face one another and blast at one another with short barks of this sort, meanwhile “threatening” by opening their mouths. Since they live immersed in an acoustic world quite strange to us, we have great difficulty in appreciating the full life of these animals with respect to one another and their environment. From birth they are constantly bombarded with signals from the other animals of the same species and by echoes from the environment which they can apparently use very efficiently. Their ultrasonic (to us) emissions are not merely “sonar,” but are interpersonal and even emotional. These animals are not inanimate, cold pieces of sonar apparatus. They use their ultrasounds and their high-pitched sounds interpersonally with fervor in everything they do.[15]