Pax feedback to (NOV) unusual sound heard from middle of train. Staff(ORC) checked Front M2 & Rear M 2 cars. no abnormal sound heard. Pax feedback to (NOV) weirdsound coming from middle of train. Staff(ORC) checked Front  ~~~~~ 2536 & 2535 Pax feedback to (NOV) unusual sound heard. Staff (ORC) checked 2536 & 2535 cars. no abnormal sound heard.  2536 Checked wheels & dump valve for abnormalities - OK. 2535 Found wheel uneven grooving. Dump valve test - OK. Notification 2471788 raised for profiling. Sarma/Sugu/Kamar/Anand 45003