Don Schrickel, a Chicago businessman whose work often takes him to South America, is learning Spanish -- over the telephone. Three times a week, Schrickel receives a call in his office from his Spanish instructor in New York City. The 25-minute lessons have been going on for a year and a half and currently focus on the specialized agricultural vocabulary Schrickel needs for his grain research and development work.

"The major advantage of learning a foreign language by phone is flexibility," says Schrickel. "I can do it in my office, at my convenience, and reschedule lessons whenever I have a conflict."

Schrickel's instructor, Senora Pilar Martinez, is an employee of Phonelab, a New York City company founded in 1973, which offers 14 languages by telephone. Phonelab's prices start at $270 for six weeks of three lessons per week.

Not everyone agrees that learning a foreign language by telephone is effective. "We believe face-to-face instruction is necessary," says Elio Boccitto, vice-president for Berlitz Schools of Language. Berlitz operates over 215 language schools throughout the world and charges its students -- over half of whom are business people -- between $15 and $23 for a 45-minute lesson.