If your matches have tested at fewer markers than you, you will want to encourage them to upgrade to see if the match holds up. You will be able to see the Most Distant Ancestor for your matches who have provided them. Look down the list to see if any look familiar.
In physics, sound is a vibration that propagates as a typically audible mechanical wave of pressure and displacement, through a medium such as air or water. In physiology and psychology, sound is the reception of such waves and their perception by the brain.
(Å­lâ²trÉ-soundâ²) 1. Sound whose wave frequency is too high (over 20,000 hertz) to be heard by humans. 2. The medical use of ultrasound waves, especially to produce images of the inside of the body or to observe a developing fetus.