How does soundproofing affect a hearing test?

Question

How would it affect the frequency of sound and sound pressure

Answer 1

In a hearing test, a pure tone (hum, whistle, etc) is played through headphones and its volume is varied until the tester finds the faintest sound that you can hear. This test is repeated with tones at various frequencies, to see how sensitive you are to high and low pitched sounds. If your hearing has been damaged by exposure to loud sounds, this will show up as a loss of hearing sensitivity of around 4,000 Hz.
Obviously, you need to ensure that there is no background noise in the test room that might prevent you from hearing the very faint test sounds, so the room has to be soundproofed against other noise.

Answer 2

Hearing is relative. We hear things relative to the ambient background noise. The audio source used in hearing tests is absolute. It depends on the amount of electrical energy input to the headphones. To hear a particular frequency, the sound must be louder than the background, at that same frequency. The purpose of soundproofing is to reduce the background to as near zero as possible. The object of the test is determine absolute hearing acuity, which is only possible if the background is zero. Let me rephrase that: Hearing is relative to the background. However, an absolute measurement can be made if the background is reduced to zero. (At the frequency of interest.) That is the purpose of the soundproofing.

Sound pressure level is a function of the total acoustical energy present (source and background) at all frequencies, measured simultaneously. The frequency of the sound is determined by the control settings of the source's electronics. The frequencies present in the background are determined by the ambient environment minus the frequencies absorbed by the soundproofing.

Let me tell you a true story which is relavent here. When I was a student, I took a summer job in an automobile assembly plant. As a new hire, I was required to take a hearing test. They put me in a "soundproof" box and put the phones on my head. The sounds of the factory just outside the nurse's office were plainly audible, but the loudest sound was the muffin fan used to ventilate the box. I flunked the test and was told my hearing was so poor I would have to be terminated. Because I was a physics student I was suspicious of the test and went directly to the library to read-up on audiology. (Which is why I know these things.) Next day, I went back to the factory, explained what I had learned and asked for a re-test. It was denied. They'd decided I was hearing impaired and that was that. My family's next door neighbor was a lawyer who specialized in representing the handicapped. He wrote the company a "nasty-gram" threatening an expensive lawsuit. A few days later I was retested. This time, in the evening so the assembly line was shut down and the stupid muffin fan was switched off. My hearing, using the same equipment in a quiet environment, tested slightly better than normal and I got the summer job.

Hope you find the information useful and the anecdotal story entertaining........................

Answer 3

Conducting the hearing tests in soundproof rooms is done to block out all the background clutter. Many of the sounds done during those test are so faint that blocking out as much noise as possible is required. Even my own breathing gets annoying during those tests and at times my own heart beat can get in the way. Imagine having to do it with real noise getting in the way!

Answer 4

The soundproofing cuts out external noises, but does not affect a hearing test

Answer 5

Hi. It is meant to keep sound out of the chamber. Most tests use headphones. The pressure levels and sound frequency and dB are controlled within them.

Answer 6

I'm sorry, you'll have to speak up. This bl**dy soundproofing is ruining my social life. Could you repeat that?

Answer 7

could you speak speak up louder?

Answer 8

sorry?