Theo At 193 Days!
He is hiding there somewhere!
He is hiding there somewhere!
Ultrasound is a cyclic sound pressure with a frequency greater than
the upper limit of human hearing, this limit being approximately 20
kilohertz (20,000 hertz).
The upper frequency limit in humans (approximately 20 kHz) is caused by
the middle ear, which acts as a low-pass filter. If ultrasound is fed
directly into the skull bone and reaches the cochlea without passing
through the middle ear, much higher frequencies can be heard. This
effect is discussed in ultrasonic hearing. Carefully-designed scientific
studies have been performed and confirmed what they call the hypersonic
effect - that even without consciously hearing it, high-frequency sound
can have a measurable effect on the mind.
Ultrasound is used routinely in obstetric appointments during pregnancy, but the FDA discourages its use for non-medical purposes such as fetal keepsake videos and photos, even though it is the same technology used in hospitals.
Obstetric ultrasound is primarily used to: