The phrase "tiny grooves" refers to small cuts or ridges on a surface. It means there are very thin lines or channels present that can be seen or felt. Full definition
This helps get the wax into tiny grooves and crevices. (inmyownstyle.com)
Made on discs and cylinders ~ six of his fragile recordings were brought to life thanks to advances in technology that enabled the sound to be recovered from tiny grooves with light and a 3D camera.Some of the recordings included the reciting of Shakespeare's verse ~ «To be ~ or not to be» ~ counting 1 -2-3 and a trill of the tongue. (educationworld.com)
Made on discs and cylinders ~ six of his fragile recordings were brought to life thanks to advances in technology that enabled the sound to be recovered from tiny grooves with light... (educationworld.com)