English Letter Frequencies in Transcribed Speech versus Written Samples

This study examines the frequency of letters of the alphabet as a function of their origin in writing or in transcriptions of speech. Data were derived from two sources, both in English. One source was from a previous publication and included written and speech samples of approximately 2,400 words each from six subjects. A second source derived from a previous study that developed an estimate of English letter frequencies using a sample of 320,780 words from an article by Whissell (1998). The combined results showed remarkable consistency of English letter frequencies across different types of sources, providing further evidence of the stability of English letter frequencies.