公开(公告)号：US20150023515A1

公开(公告)日：2015-01-22

申请号：US14332820

申请日：2014-07-16

Applicant: GN Netcom A/S

Inventor： Jacob REIMERT

IPC: H04R1/10

CPC classification number: H04R1/1083 ,  H04R1/1008 ,  H04R1/2819 ,  H04R1/2834 ,  H04R3/002 ,  H04R2410/05 ,  H04R2460/01

Abstract: The present invention relates to an earphone (1, 201, 401, 601) with noise reduction, i.e. an earphone adapted to attenuate acoustic noise approaching a wearer's ear (7).The present invention aims at providing an earphone (1, 201, 401, 601) that may simultaneously allow achieving high-level low-frequency sound and effective noise reduction. This is achieved by an earphone (1, 201, 401, 601) adapted to provide an acoustic output signal to an ear (7) of a wearer in dependence on an earphone audio signal. The earphone (1, 201, 401, 601) is further adapted to be arranged on the wearer's head (2) in an operating position such that a front cavity (5) between the head (2) and the earphone (1, 201, 401, 601) is separated from ambient space (6). The earphone (1, 201, 401, 601) comprises: a housing (3) having a wall (9) separating a rear cavity (10) with an acoustic compliance from the front cavity (5) and from ambient space (6); an ear cushion (4) arranged and adapted to attenuate acoustic signals entering the front cavity (5) from ambient space (6) when the earphone (1, 201, 401, 601) is in the operating position; a first diaphragm (11) reciprocatably suspended across a first through hole in the housing wall (9) between the front cavity (5) and the rear cavity (10) and adapted to be actively driven to provide at least a portion of the acoustic output signal; and a second diaphragm (13) reciprocatably suspended across a second through hole in the housing wall (9) between the rear cavity (10) and ambient space (6) such that the second diaphragm (13) and the rear cavity (10) constitute an acoustic resonant system (10, 13) with an acoustic resonance at a resonance frequency. The earphone (1, 201, 401, 601) is characterized in that the acoustic resonant system (10, 13) is configured such that the resonance frequency is below 500 Hz.The second diaphragm (13) attenuates acoustic signals entering the rear cavity (10) from ambient space (6) at frequencies above the resonance frequency and virtually increases the acoustic compliance of the rear cavity (10) at frequencies below the resonance frequency. The earphone (1, 201, 401, 601) thus behaves as an acoustically closed earphone at frequencies above the resonance frequency and as an acoustically open earphone at frequencies below the resonance frequency.