(Tape) Recorder Guidelines
1.
Use a good (tape) recorder that accepts an external microphone. (Do NOT use
a miniature tape recorder!!) 
2.
Optimally, use a high quality, separate microphone. 
(frequency response: 50 - 18,000 hz)
The subject's mouth should remain approximately 12 inches from the microphone.
3. The sample should be digitized at cd-quality: digitized at 44.1 KHz., 16 bit mono. The file can be a .wav file, an .aiff file, a quicktime movie file, etc.: