The subject in our study has spent between 2000 and 2500 h learning to read speech spectrograms. We tested the subject's ability to identify the phonetic content of broadband speech spectrograms of unknown utterances during eight separate sessions of about 4 h each. The expert was presented with 23 spectrograms of English sentences and sequences of words and nonsense words, and 50 English words embedded in a known carrier phrase. The phonetic labels produced by the expert agreed with the phonetic labels produced by trained phoneticians (who listened to the speech) between 80% and 90% of the time, depending upon the scoring method used. When presented with words in a known carrier phrase, labeling performance improved to about 95%. A linguist who was presented with the phonetic transcriptions produced by the spectrogram reader was able to identify all of the words in 10 of 15 utterances, and missed only a single word in each of the remaining five. A film will be shown of the expert segmenting and labeling two spectrograms of unknown utterances.