Hearing protection device evaluation apparatus
First Claim
1. A portable hearing protection device measuring apparatus for determining the noise attenuation of a muff type hearing protection device worn by a person in a noisy environment, said apparatus comprising:
- two microphones, one for detecting noise outside a muff, the other for detecting noise inside the muff, said microphones detecting noise received by each microphone simultaneously and providing input signals;
circuitry for receiving the input signals and for providing an output including a single number output representing a difference between the noise detected by the two microphones; and
a display for displaying the single number output.
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Accused Products
Abstract
A portable hearing protection device evaluation apparatus which can be taken into the field to measure noise attenuation of a muff type hearing protection device under actual working conditions is provided. The apparatus includes two miniature microphones, one positioned inside a muff near the ear, the other positioned outside the muff to detect the noise in the environment. These two microphones simultaneously receive input signals which are provided to circuitry which determines and displays a single number output representing the noise attenuation.
66 Citations
18 Claims
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1. A portable hearing protection device measuring apparatus for determining the noise attenuation of a muff type hearing protection device worn by a person in a noisy environment, said apparatus comprising:
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two microphones, one for detecting noise outside a muff, the other for detecting noise inside the muff, said microphones detecting noise received by each microphone simultaneously and providing input signals; circuitry for receiving the input signals and for providing an output including a single number output representing a difference between the noise detected by the two microphones; and a display for displaying the single number output. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A portable hearing protection device measuring apparatus for determining the noise attenuation of a muff-type hearing protection device while it is worn by a person in a noisy environment, said apparatus comprising:
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a first microphone for detecting noise on the outside a muff; a second microphone for detecting noise inside the muff near an ear of the person, said first microphone and said second microphone providing input signals which represent detected noise; circuitry for receiving the input signals and for providing an output signal representing noise attenuation of the muff; and a hand held housing for enclosing the circuitry, said housing including a user interface. - View Dependent Claims (12, 13, 14, 15, 16)
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17. A method for testing a muff-type healing protection device in a real environment in which a person would normally experience noise while the device is worn by the person, said method comprising the following steps:
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positioning a first microphone inside a muff, near an ear of the person; positioning a second microphone outside and on or near the muff, said second microphone for receiving noise in an environment in which the person would regularly experience noise; receiving signals from each of the first and second microphones; generating from the signals an output signal including a single number output which represents noise attenuation due to the muff; and displaying the single number output on a portable, hand-held user interface.
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18. A portable hearing protection device measuring apparatus for determining the noise attenuation of a muff-type hearing protection device while it is worn by a person in a noisy environment, said apparatus comprising:
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a first microphone for detecting noise outside a muff; a second microphone for detecting noise inside the muff and near an ear of the person, said first microphone and said second microphone providing input signals which represent detected noise; circuitry for receiving the input signals and for providing an output signal representing noise attenuation due to the muff; and a portable user interface for receiving the output signal and for displaying sound attenuation information to a user.
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Specification