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Occlusion Effect
The occlusion effect occurs when an object fills the outer portion of a person's ear canal, causing that person to perceive echo-like "hollow" or "booming" sounds generated from their own voice. The bone-conducted sound travels to the cochlea through different pathways. The outer ear pathway corresponds to the sound pressure generated in the ear canal cavity due to the vibration of the ear canal wall, which constitutes the source of the occlusion effect. At low frequencies, the outer ear pathway is negligible when the ear canal is open but dominates when it is occluded. The occlusion effect is thus objectively characterized by an acoustic pressure increase in the occluded ear canal at low frequencies and which can be measured with a probe-tube microphone. Considering that the vibrating ear canal wall acts as an ideal source of volume velocity (also known as volumetric flow rate), the occlusion device increases the “opposition” of the ear canal cavity to the volume velocity imp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hearing Aid
A hearing aid is a device designed to improve hearing by making sound audible to a person with hearing loss. Hearing aids are classified as medical devices in most countries, and regulated by the respective regulations. Small audio amplifiers such as personal sound amplification products (PSAPs) or other plain sound reinforcing systems cannot be sold as "hearing aids". Early devices, such as ear trumpets or ear horns, were passive Amplifier, amplification cones designed to gather sound energy and direct it into the ear canal. Modern devices are computerised electroacoustic systems that transform environmental sound to make it audible, according to audiometry, audiometrical and cognitive rules. Modern devices also utilize sophisticated digital signal processing to try and improve speech intelligibility and comfort for the user. Such Digital signal processing, signal processing includes feedback management, wide dynamic range compression, directionality, frequency lowering, and noi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
