Hello classmate, first of all, I deeply sympathize with your experience.
I think this test center’s attitude is very irresponsible. As the location of the examination center, this school did not properly stagger the different arrangements according to the school calendar, which resulted in the chorus interfering with the examination.
You have two ways to file a complaint:
1 - Find ETS’s domestic spokesperson NEEA, which is the Examination Center of the Ministry of Education.
2 - Contact the US ETS headquarters directly.
I suggest you first do 1 and then 2, just write an email and send it to their customer service. If you have other candidates who are willing to support you on the day, you can ask them to sign it after you have written it. Scan the signed complaint form into your computer and send it as an attachment. If NEEA ignores you, you can translate all your emails and attachments into English, and then email or fax NEEA's reply to ETS.
If you feel like forget it and let the matter rest after you are angry, then consider this time as a way for you to gain experience in the examination room. If you can avoid this examination point in the future, just avoid it. If you can’t afford to offend me, avoid it. Affordable.
If you take the TOEFL test in the future and discover the situation in the choir before the test, you can lodge a protest before the test starts and before signing in.
In any case, I wish you GOOD LUCK :-)