A system for generating audio impressions of data for a visually-impaired user. The system receives data that is displayable by a chart. The data comprises a plurality of values. The system generates an audio impression of the received data. The audio impression includes a first portion and a second portion. The first portion is based upon at least a first value of the received data. The second portion is based upon at least a second value of the received data. An audible difference between the first portion and the second portion reflects the magnitude of a difference between the first value and the second value.
