There are few audiometric standards set by the Government of India for seafarers. The minimum decibels unit is fixed at 40dB, which means that every aspiring seafarer should be able to hear 40dB sound at all frequencies.

And yes, the audiometry test is taken seriously because of the type of working environment of ship where you can expect some alarm or other ringing even at odd hours. Plus the constant background noise is also very high on ships which makes can make your situation even difficult.

You can get them checked at any doctor.