초록 ▼

Improvement in active noise reduction based on a negative feedback electro-acoustical system which consists of an Electronic Earplug seated in the concha fossa combining active and passive noise reduction in the quiet zone at the ear, a bilateral transducer circuit which drives a speaker as an acous

Improvement in active noise reduction based on a negative feedback electro-acoustical system which consists of an Electronic Earplug seated in the concha fossa combining active and passive noise reduction in the quiet zone at the ear, a bilateral transducer circuit which drives a speaker as an acoustical velocity source, a shunt feedback control filter network which improves stability and increases noise reduction, and a combined input noise-filter/feedback system. A typical application is in a noisy environment for hearing protection and for improved communication capability, e.g., in vehicular communication, telephone, intercom, hearing aids, and stethoscopes.

대표청구항 ▼

An earplug for placement in an ear canal with communication capability provided by a speaker, comprising: a speaker for converting an electrical signal into an acoustical output; a summing microphone; an external active noise reduction circuit; a cable connecting the speaker and the summing micropho

An earplug for placement in an ear canal with communication capability provided by a speaker, comprising: a speaker for converting an electrical signal into an acoustical output; a summing microphone; an external active noise reduction circuit; a cable connecting the speaker and the summing microphone to said external active noise reduction circuit; an enclosure for supporting said speaker, said summing microphone, and said cable; a hollow earplug adapter, the enclosure being mounted inside of said hollow earplug adapter, the enclosure and said earplug adapter having openings allowing close acoustical coupling among the speaker, the summing microphone, and the ear canal; and said hollow earplug adapter forming an acoustical seal between the enclosure, a concha fossa and/or an ear canal wall, thereby acoustically isolating a small volume of the ear canal from ambient noise providing a quiet zone for active noise reduction.