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
Comparison of analog and digital recording 10 Hz to above 20 kHz. Some analog tape manufacturers specify frequency responses up to 20 kHz, but these measurements may have been made at lower signal levels. Compact Cassettes may have a response extending up to 15 kHz at full (0 dB) recording level. At lower levels (-10 dB), cassettes are typically limited to 20 kHz due to self-erasure of the tape media. The frequency response for a conventional LP player might be 20 Hz - 20 kHz +/- 3 dB. Unlike the audio CD, vinyl records and cassettes do not require anti-aliasing filters. The low frequency response of