echo-, ech-

(Greek: sound, noise; especially a returned sound; repetition, imitation)




anecho
anechoic (adjective)
Free from or without echoes: "The scientist was experimenting with the absorption of sound waves and radar signals in a special anechoic chamber."
catecheses (plural)
catechesis (singular)
catechetical
catechism
catechist
catechization
catechize
catechizing
catechumen
echo
echoacousia, echoacusis
The subjective experience of hearing echoes after normally heard sounds.
echocardiogram
1. A medical test which uses high-frequency sound waves to image the heart and surrounding tissues.
2. An image of the heart produced by ultrasonography or a test that uses sound waves to create a moving picture of the heart.

The picture is much more detailed than x-ray images and involves no radiation exposure.

echocardiograph
An ultrasound device used to examine the working heart and display moving images of its action.