In the past, the voices of these millions were usually heard singing patriotic songs or offering party slogans in sweet treble tones. Now, as Soviet press institutions react to Mikhail S. Gorbachev's call for openness, the limits on what young people can say are being stretched, and their voices are sharp and unforgiving.
''We are dirty, we are crude, but all the same we are your children,'' says a young Latvian punk rocker in a controversial and highly popular new documentary film that is filling Moscow theaters, ''Is It Easy to Be Young?''
Another film blames the older generation for ''the lies that created us.''
''Is it easy to be young?'' asks a Latvian youth, in words that gave the film its title. ''No. I walk out on the street and the militiaman sees this'' - he turned his head to show his pony tail -''and takes me down to the station.''
In the latest issue of the journal Yunost, a drug addict, Oleg T. Dukhovnii, writes: ''Nothing caught my attention, as mama said. Nothing held my interest. For a month I just kept on using drugs, not understanding that I was hooked.'' Hard Work Seen as Useless
Although more such images of alienation show up in the arts, sociologists are producing statistical portraits of young people who try to create their place in Soviet society through hard work but quickly find it will neither advance their careers nor feather their nests.
A Soviet sociologist, Valery A. Mansurov, said in an interview with a Western correspondent: ''A young man may well see the situation as hopeless.'' He added that the young man ''may work very well, but there is a line'' beyond which there will be no extra reward for extra work.
The single greatest source of dissatisfaction among young men, he said, is housing. A chronic shortage of housing - even though 1985 was a record year for construction of dwelling units -forces many young men to live with their parents or in huge, drab workers' dormitories built on the outskirts of Moscow and other large Soviet employment centers.
Official Soviet sources estimate that 70 percent of young people change jobs or careers as a direct result of housing dissatisfaction. Housing is generally distributed by factories, institutes and other employment centers, with seniority a key criterion of eligibility.
Even if a young man gets a satisfactory apartment, Mr. Mansurov said, the cost of furnishing it and supporting a family may be beyond his means. ''This dependence,'' Mr. Mansurov said, ''creates a sense of hopelessness.
''He begins to think: 'My level of material life depends not on me but on parents, relatives and my factory. So what's the point of trying?' ''
The crowded housing, he added, encourages early marriages, since marriage and family allow young people to jump ahead on housing eligibility lists. But the crowding and the financial dependence on parents also lead to early divorces, Mr. Mansurov said.
Soviet statistical journals report that, in the 25-to-29 age bracket, for every 10 women married in 1985, 6 were divorced. And three-quarters of the men that age who married were doing so for the second or third time. No More Western Poison
There are official attempts to ease or channel the dissatisfaction of the young. Rock music has lost its reputation as a Western poison and can be seen on Soviet prime-time television. So can break dancing and satiric caricatures of previously untouchable figures like scholars or heads of institutes. Komsomol 'Bureaucratic'
And although the Communist youth organization Komsomol is still deferred to as the vanguard of Soviet youth, it seems largely irrelevant. It was criticized recently by the Soviet press agency Tass as ''formal and bureaucratic.''
Although official Communist organizations are heard from somewhat less among the babble of newly unedited voices, some of the old, carefully crafted ideals of Soviet heroism are also being slightly transformed or avoided.
In ''Is It Easy to Be Young?'' veterans of the Soviet war in Afghanistan are shown describing the brutality they saw. They pay lip-service to the rightness of the Soviet cause and the eternal verities of war, but a world-weariness hovers about them, as does a latent anger reminiscent of America's Vietnam-era veterans.
One said his time in Afghanistan had only put him years behind his fellows at school and at work. He compared himself to a child who has been forced to repeat a grade.
Another mused eloquently on what combat has done to the man he was. ''The feeling that I have that I have done something dirty, something not really human, will remain with me,'' he said. ''A stain is sure to remain on me.''
