The Thinklabs One provides several frequency filters through which you can amplify various body sounds. By default, the One is pre-set with two "favorite" filters that enable you to quickly and easily transition between two frequently used frequencies. Favorites can include low-frequency filters for heart sounds, high-frequency filters for lung sounds, or full bandwidth for unfiltered sounds.

To switch between the favorite filters, click and release the Filter control button as shown on the image to the left. The two LEDs illuminated on the Filter Scale will "jump" from one favorite to the other. If you would like to select filters other than the pre-set options, follow the steps below.