| 摘要 |
An ear-worn speaker carrying device (“ESD”) incorporating active ambient noise reduction circuitry is provided with a seal intended to contact or surround the ear of a user; the seal being intended to present a substantial impedance to inward or outward transmission of sound to or from the ear. At least one acoustic channel of predetermined dimensions bypasses the seal to providing an acoustic leakage path of known characteristics, thereby permitting predetermined levels of sound to enter and exit by way of the channel, such that minor variations in leakage, dependent, for example, upon precise mounting of the seal to the ear as used from time to time, are rendered relatively unimportant. In a preferred embodiment, the device further comprise conduit connected to vent the speaker's rear surface to the external ambient, and respective exit apertures for the acoustic channel and the acoustic conduit are so relatively located that sounds exiting from them tend to cancel each other, reducing sound emissions from the device.
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