The phrase "are only heard" is correct and usable in written English.
It can be used to indicate that something is audible or can be perceived by hearing, often in a specific context or condition.
Example: "The whispers in the library are only heard when the room is completely silent."
Alternatives: "can only be heard" or "are heard exclusively".
We begin to realise that we are only heard when we commit violence.
At the same time the ENO struggles to fill seats and, as Ian Jack reports (5 December), classical lieder are only heard at one or two centres, such as the Wigmore Hall.
All of these characters, even those off-screen who are only heard (such as Brooke's father) or who are not even heard (Brooke's boyfriend, Stavros), acquire an extraordinary density, their dialogue gaining spin and lilt, from their place in the action.
We talk a lot about the Tibet we see from the outside, but as Robert Barnett, one of a handful of western scholars who understand the country, tells us in his introduction, the voices of the Tibetan people are only heard in "snatches and fragments".
Often, the voices of disadvantaged, minority groups are only heard only when those who come from more privileged backgrounds speak on their behalf.
In The Female Persuasion, those increasingly loud voices in today's feminism ― the voices of black women, Muslim women, trans women, and others ― are only heard as faint echoes, and the speakers seen only through a glass, dimly.
"We are only hearing about market mechanisms in the conference.
The group is developed and ready, yet most of us are only hearing it now as it should have been heard long ago: on a good record and in the Vanguard's sonic environment.
"We are only hearing what the police are saying.
Remember you are only hearing one side of the story and most people paint themselves in a favorable light.
"With the teacher shortage and with new funding for schools, we are only hearing [of] a very limited number of pink slips to date," Myslinksi said.
