CONTENTS 



Page 



6 INTRODUCTION 



7 I. THE UNDERWATER SPARK SOUND SOURCE 

 7 Design Considerations 



16 Theoretical Discussion 



18 Tests and Measurements 



32 Experiments with a Magnetic Gap 



37 Experiments with Resonators 



37 II. THE PNEUMATIC SOUND SOURCE 



37 Background 



43 Early Experiments 



44 Design Considerations 

 50 Theoretical Discussion 

 55 Tests and Measurements 

 58 The Acoustic Bomb 



58 III. OTHER NOVEL SOUND SOURCES 



58 Conversion of Heat to Sound 



60 The "Wolf Whistle" 



62 CONCLUSIONS 



62 I. The Underwater Spark Sound Source 



62 II. The Pneumatic Sound Source 



6 3 RECOMMENDATIONS 



6 3 I. The Underwater Spark Sound Source 



6 3 II. The Pneumatic Sound Source 



