human
what is a "screeching noise"
gpt
Screeching noise is an unpleasant noise created usually when two hard surfaces rub against each other. A common example is a sound of fingernails on a black board.
human
By that definition, dragging a brick on pavement would make a screeching noise, but it doesn't. Are there any more requirements to create a screeching noise?
gpt
The velocity of sound waves when conducted by a material varies according to the density and stiffness of the material. Concrete is a porous material that absorbs more energy from contact and has a lower frequency response, while the porcelain enameled steel used in chalkboards is far more dense and inelastic which emits stronger sound waves at a higher frequency during contact.