The Sound and Feel of Titrations: A Smartphone Aid for Color-Blind and Visually Impaired Students

An Android-based application has been developed to provide color-blind and visually impaired students a multisensory perception of color change observed in a titration. The application records and converts the color information into beep sounds and vibration pulses, which are generated by the smartphone. It uses a range threshold of hue and saturation coordinates of the HSV (hue, saturation, value) color space for detecting a color change specific to an indicator for, e.g., shades of pink for phenolphthalein-based titration, and informs the users before and upon attaining the end point. This approach can enable color-blind and visually impaired students to actively perform a fairly routine laboratory activity of titration.