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.
sound noun (NOISE) A2 [ C or U ] something that you can hear or that can be heard: They could hear the sound of a bell tolling in the distance. She stood completely still, not making a sound. Suddenly we heard a loud knocking sound from the engine. Sound can travel over very large distances in water.