The sound recordings in The Center for Applied Linguistics Collection were made from 10 1/2 inch audio tapes recorded at a speed of 7 1/2 inches per second, dual track mono. The analog audio from the tapes was converted to PCM digital audio and stored in the WAVE file format.
The preservation WAVE files were created at a sampling rate of 96,000 samples per second and 24-bit word length. Three derivative copies of the recordings were created through a batch conversion process. WAVE files were created at a sampling rate of 44,100 samples per second and 16-bit word length. MP3 and RealAudio files were created at a constant bit rate of 256 kilobits per second and a sampling rate of 44,100 samples per second.
Transcriptions were scanned onsite by the ITS Digital Scan Center at the Library of Congress. All scans were done at 300 dpi resolution.
Collectors provided transcriptions for approximately half of the recordings. These were converted to text when 50% or more of the transcription was legible. The text was not edited to correct typographical or other errors in the original transcriptions, however, linguistic notations were removed and notes were added to indentify unintelligible words or sections. Gaps in the transcriptions were also noted. Images of the transcriptions are available on the website for users who want to see the original documents. Some of the transcriptions in this collection are incomplete.