Can European Community talk in fewer tongues?

The world's largest interpretation and translation service - charged with unscrambling the ramblings of delegates and documents at European Community headquarters here - may be in for some tough times.

Within years the service, which already has its hands full with seven tongues , will face the daunting prospect of making sense of two new languages when Spain and Portugal join the 10-nation group.

''It will be impossible, absolutely impossible,'' says British interpreter Michael Ralph, who like the EC's stable of some 500 interpreters knows that interpreting nine languages simultaneously would mean having at least 30 interpreters present at a single meeting. ''In most cases,'' Mr. Ralph says, ''there would be more interpreters than participants.''

Not only would the technical problems be enormous, but also the cost of running the service (now about $450 million a year) could double, experts say.

In addition to the interpreters, the service employs about 500 translators to reword the more than 1 million pages of documents cranked out by the EC every year (about 5,000 pages per working day).

For them, special translating machines now being developed may be able to ease the burden some day. But for interpreting, humans may be irreplaceable.

One idea being kicked around by EC planners is to limit the number of working languages to two or three (English, French, and probably Spanish). That, however , would almost certainly be unacceptable to many countries, who would argue that under the EC treaty, every community language must enjoy ''equal status.''

''Any limitation of the number of languages used by the community institutions,'' says Kai Nyborg, chairman of the European Parliament's Rules Committee, ''would interfere with the democratic nature of the community. Even though the community's language arrangements are expensive and require a large staff, the committee's view is that they are based on important democratic principles that we should be very careful not to violate.''

The parliament's Political Affairs Committee, however, has not only called for the reduction of the number of languages used to two or three (within 15 years) but also urged the education ministries in the EC countries to confine their syllabuses for language teaching to two or three languages to provide the next generation with ''the necessary means for communication within the community and in an international context.''

''A united Europe,'' the committee said in a recent report, ''must be politically articulate. . . . This is not possible in a Tower of Babel.'' Faced with similar problems, the report points out, the United Nations and other international organizations have limited the number of working languages they use.

Another possible solution has been put forward by the head of the EC's interpretation service, Renee Van Hoof, who says the so-called ''asymmetric'' system (allowing everyone to speak in his or her own language with interpretation provided into only the most widely understood languages) may be the answer.

But this, too, has been criticized in some quarters, especially the European Parliament. Some have even suggested scrapping all the community's ''natural'' languages and replacing them with one ''artificial'' language, such as Esperanto. Van Hoof calls this ''utopic.''

Practical steps toward solving the problem may be years away. But few here dispute Dr. Theodor Holtz, an adviser to the EC on the subject.

''We must admit,'' Dr. Holtz wrote, ''that democracy cannot function without communication. Where there is no communication, there can be no real preparation of decisions . . . and opportunities for rational solutions of conflict diminish.''