Acoustic microscopy acoustic microscope (CSAM), and C-mode scanning acoustic microscope (C-SAM). More recently acoustic microscopes based around picosecond ultrasonics systems have demonstrated acoustic imaging in cells using sub-optical wavelengths working with ultrasonic frequencies into the multi-GHz. Since the vast majority of acoustic microscopes in use today are C-SAM type instruments, this discussion will be limited to these instruments. Ultrasound is broadly defined as any sound having a frequency above 20 kHz, which is approximately the highest frequency that can be detected by the human ear. However, the acoustic microscopes emit ultrasound ranging from 5 MHz to beyond 400 MHz so that micrometre
Perception of infrasound the right source loudspeakers when they were positioned at different angles from the elephant’s head. The elephant could localize sounds best at a frequency below 1 kHz, with perfect identification of the left or right speaker at angles of 20 degrees or more, and chance level discriminations below 2 degrees. Sound localization ability was measured to be best at 125 Hz and 250 Hz, intermediate at 500 Hz, 1 kHz, and 2 kHz, and very poor at frequencies at 4 kHz and above. A possible reason for this is that elephants are very good at using interaural phase differences which