14th International Congress of Phonetic Sciences (ICPhS-14)

San Francisco, CA, USA
August 1-7, 1999


How Well Do Humans Recognize Spellings in German Telephone Speech?

Christoph Draxler

Department of Phonetics, University of Munich, Germany

We have set up a WWW-based experiment to measure the performance of humans in a spelling task. This measure can then be used as a baseline for the evaluation of automatic spelling recognizers. The speech material consists of 500 spellings of artificial words of the German SpeechDat(II) database of telephone speech. Each test person listened to 40 spellings via a WWW browser and entered the letters he or she heard into a database via a form. A total of 105 persons participated, but only some were able to complete a full session. The overall results show that 50.0% of all spellings were recognized exactly. In 37.0% letters were substituted by other letters, and in 13.0% letters were missing or inserted. For spelling by letters, the incorrect recognitions can be attributed to phonetic proximity of the letters names. Spelling by name eliminates incorrect recognitions because of phonemical proximity, but introduce new errors.

Full Paper

Bibliographic reference.  Draxler, Christoph (1999): "How well do humans recognize spellings in German telephone speech?", In ICPhS-14, 231-234.