HAMTRAMCK, Mich., April 30— To hear people in this blue-collar city tell it, things were fine until the al-Islah Islamic Center petitioned to broadcast its call to prayer, or azan, over an outdoor loudspeaker.

Masud Khan, the mosque's secretary, sat on the carpeted floor on Wednesday and reflected on what he had learned about some of his neighbors in the last few months. ''How much they hate us,'' he said softly.

Jackie Rutherford, a librarian and youth-care worker, sat on her front stoop watching three men in Islamic shirt-dresses and tupi caps at the house across the street. ''I don't know what's going to happen to our little town,'' said Ms. Rutherford, 39.

''I used to say I wasn't prejudiced against anyone, but then I realized I had a problem with them putting Allah above everyone else,'' she said, of the plan to amplify the call to prayer, which mosques announce five times a day. ''It's throwing salt in a wound. I feel they've come to our country, infiltrated it, and they sit there looking at us, laughing, calling us fools.''

For the population of Hamtramck, a city of 23,000 surrounded by Detroit, the battle of the loudspeaker, which the City Council approved on Tuesday, has revealed a crossfire of religious, ethnic and lifestyle grievances, aggravated by the lingering memories of Sept. 11, 2001, which left many Muslims here feeling they were under suspicion.

Once an enclave of Polish immigrants, Hamtramck has since the 1990's become a haven for immigrants from Bangladesh, Yemen, Pakistan, Bosnia and other countries, including a large Muslim population. In the 2000 census, 41 percent of the city's population was born outside the United States.

On spring afternoons the sidewalks of Joseph Campau Avenue echo snatches of Polish, Bengali, Arabic and hip hop, punctuated by the sound of bells from several Catholic churches. Three mosques have opened in the last few years, increasing in size while the congregations at neighboring Roman Catholic churches dwindle.

Yet for all this churn, the ethnic populations coexisted with little overt friction.

''Even after 9/11 we had no problems,'' said Abdul Motlib, the president of the al-Islah mosque, which serves a mostly Bangladeshi membership (the other two mosques are primarily Bosnian or Yemeni).

Then last year Mr. Motlib applied for approval to amplify the call to prayer, a sonorous invocation in Arabic that lasts up to two minutes.

For some longtime residents, like Joanne Golen, 68, who described herself as a born-again Christian, the request crossed a line. Mrs. Golen said she had always gotten along well with the Bangladeshi families in her neighborhood. She noted that at Easter one of her new neighbors brought her a turkey that he had gotten at work. But she said the call to prayer was too much.

''My main objection is simple,'' she said. ''I don't want to be told that Allah is the true and only God five times a day, 365 days a year. It's against my constitutional rights to have to listen to another religion evangelize in my ear.''

At City Hall on Tuesday, before the final vote on the loudspeaker, a crowd of more than 100 crammed into a room, with dozens more listening or arguing in the hallway outside.

Chuck Schultz, 49, a computer programmer from nearby Grosse Point, spoke against the measure.

''Everyone talks about their rights,'' Mr. Schultz said. ''The rights of Christians have been stripped from them. Last week there were Muslims praying downstairs, in a public building. If Christians tried to do that, the A.C.L.U. would shut us down.''

Some residents complained about the potential noise. Others, like Veronica Wojtowicz, 81, reminded neighbors of a time when life in Hamtramck was simpler.

''My parents came to this country and worked hard,'' Ms. Wojtowicz said. ''I think the grace belongs on the other side. The intolerance doesn't come from the people who object, it comes from the other side. We all lived in peace and had no problems. You moved too fast.''

In response, Abdul Latef, the imam at Masjid Al-Falah, a mosque in Detroit, asked the community to be patient.

''You can make history,'' Mr. Al-Falah said. ''This is part of our religion. If it is too noisy, then you can complain, and they will stop it forever.''

Council members emphasized that there was nothing technically preventing the mosque from amplifying its call to prayer, even without amending the city's noise ordinance, and compared the amplification to the chiming of church bells. The amendment just gave government officials leverage to limit the volume and hours of the broadcasts, said Councilman Scott Klein.

Mr. Motlib said the mosque applied for approval ''because we want to be good neighbors.''

Paradoxically, the call to prayer is one that even most of the Muslims at al-Islah mosque cannot understand, because they speak Bengali rather than Arabic, Mr. Khan said.

Yet for many Muslims in town, the dispute seemed less about noise or the content of the azan than about insecurities of an older immigrant population feeling threatened by a newer one.

''They see we are coming more and more, and they think we are taking their city,'' said Abusayed Mahfuz, 34, the editor of Bangla Amar, a local Bengali magazine and Web site. ''It's not really a religious problem. It's about migration, which is a reality.''

Mr. Musad, who moved to Hamtramck from New York in 1999, said he understood the insecurity.

''It's human nature,'' he said. ''You feel an invasion. It could happen to me also.''

Like others in his mosque, Mr. Musad said, he was drawn to the Muslim community here not for its engagement with the rest of America, but for its distance.

''What attracted me was seeing school girls with veils and burkhas,'' he said. ''It's more authentic here than in New York, more roots. There's village life.''

His regret was that Muslims were not even more isolated from the other cultures around them. ''Parents feel they need to force their kids to follow their religion, or they're going to lose their kids,'' Mr. Musad said.

And for the Polish community of Hamtramck, the clash of immigrant cultures was nothing new, said Greg Kowalski, chairman of the town historical commission. When the first waves of Polish immigrants began to outnumber their German-American predecessors after World War I, the fissures were even more profound, he said.

''The Germans looked at these Eastern Europeans and thought they were all communists,'' Mr. Kowalski said. ''There was a lot of fear. So we're really repeating history.''

Opponents of the City Council decision on the loudspeaker said they would try to reverse it, either through the courts or by a voter referendum. Unless they are successful, the mosque is expected to begin broadcasting the call to prayer in a couple of weeks. Several mosques in Detroit and nearby Dearborn already use loudspeakers, without incident.

Bashar Imam, a Muslim who runs three medical centers in Hamtramck, smarted at the venom the conflict had brought out.

''These people get treated in my medical clinics, and that's what they think of us?'' Mr. Imam said.

But he added, ''This is healthy. This is how we get to know each other.''

Photo: At a City Council meeting in Hamtramck, Mich., the Rev. James Marquis, who traveled to the meeting from Wellston, Ohio, spoke out last week against a plan by a mosque to broadcast its call to prayer. (Photo by Tom Pidgeon for The New York Times)