What to keep
- Medical ultrasound commonly uses frequencies above human hearing.
- Imaging depends on emitted pulses, tissue coupling, echoes, timing and signal processing.
- Clinical use is defined by the full device, dose, procedure and evidence—not by a frequency label alone.
A real use of acoustic frequency
Ultrasound imaging sends high-frequency sound into the body and forms images from returning echoes. Echo strength and travel time carry information about structures and movement, including blood flow.
This is non-ionising technology, but the FDA still emphasises trained operation and prudent use because acoustic energy can heat tissue and may produce mechanical effects.
The missing variables in a frequency claim
A medical device specifies far more than hertz: acoustic pressure, pulse shape, duty cycle, exposure duration, transducer geometry, coupling medium, target tissue, calibration and monitoring all matter.
Matching one frequency number on headphones cannot reproduce those conditions. The same reasoning applies whenever a therapeutic story is based on frequency alone.
What Frequency Master is for
This site is an educational audio laboratory for listening, waveform exploration and critical reading. It is not calibrated medical equipment and must not be used to diagnose, prevent or treat a condition.