US 12,342,121 B2
Microphone placement in open ear hearing assistance devices
Andrew Todd Sabin, Chicago, IL (US); Ryan C. Struzik, Hopkinton, MA (US); Aric J. Wax, Watertown, MA (US); and Daniel M. Gauger, Jr., Berlin, MA (US)
Assigned to Bose Corporation, Framingham, MA (US)
Filed by Bose Corporation, Framingham, MA (US)
Filed on Aug. 7, 2019, as Appl. No. 16/534,588.
Prior Publication US 2021/0044888 A1, Feb. 11, 2021
Int. Cl. H04R 1/10 (2006.01)
CPC H04R 1/1066 (2013.01) [H04R 1/105 (2013.01); H04R 2205/022 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A head-worn acoustic device comprising:
at least one acoustic transducer disposed such that, in a head-worn state, the at least one acoustic transducer is in an open-ear configuration in which an ear canal of a user of the head-worn acoustic device is unobstructed, and wherein the acoustic transducer is disposed within an arm of an eyeglass frame and configured (i) to radiate acoustic waves originating from a first side of the acoustic transducer through a first acoustic channel defined within the arm and (ii) to radiate acoustic waves originating from a second side of the acoustic transducer through a second acoustic channel defined within the arm;
at least two microphones configured to capture audio that is processed and played back through the at least one acoustic transducer;
an active noise reduction (ANR) circuit configured to operate on input from one or more microphones of the at least two microphones to preferentially reduce effects of (i) components of the audio captured using the at least two microphones from a first direction as compared to (ii) components of the audio captured using the at least two microphones from a second direction, wherein the ANR circuit is configured to reduce effects of audio components in a 300-1500 Hz frequency band; and
an amplifier circuit configured to process signals representing the audio captured using the at least two microphones and generate driver signals for the at least one acoustic transducer,
wherein the at least one acoustic transducer and the at least two microphones are disposed on the head-worn acoustic device such that, in the head-worn state, a lobe of a radiation pattern of the at least one acoustic transducer is directed towards the ear canal of the user,
a feedforward microphone of the at least two microphones is positioned in an acoustic null in the radiation pattern of the at least one acoustic transducer and configured to capture audio originating from behind a head of the user as a portion of the input to the ANR circuit, and
a feedback microphone of the at least two microphones is positioned outside of a direct acoustic path between the at least one acoustic transducer and an ear of the user such that an amount of coupling between the at least one acoustic transducer and the feedback microphone is substantially equal to an amount of coupling between the at least one acoustic transducer and the ear of the user.