Noise-cancelling headphone device
Provided is a noise-cancelling headphone device that prevents deterioration of reproduction frequency characteristics in a high-frequency band while preventing reduction in the reproduction output in the low-frequency band. The proposed technology is a noise-cancelling headphone device, including a speaker unit provided with a dome-shaped diaphragm having a center dome and a sub-dome, a microphone that detects ambient noise incident into the speaker unit, a baffle plate supporting the speaker unit and provided with sound emission holes to radiate reproduction sound emitted from the speaker unit, and a signal processing circuit to generate noise cancellation signal generated based on the ambient noise detected by the microphone, wherein an acoustic resistance member is provided at the position facing the sub-dome of the dome diaphragm.
1 . A noise-cancelling headphone device, comprising:
a speaker unit provided with a center dome and a sub-dome continuously surrounding the center dome and having a dome-shaped diaphragm;
a baffle plate on which the speaker unit is supported and provided with sound emission holes to radiate reproduction sound emitted from the speaker unit;
a microphone located on a side from which reproduction sound from the speaker unit is radiated, the microphone being configured to detect ambient noise entering from outside of the speaker unit to the side of the speaker unit from which the reproduction sound is radiated; and
a noise cancellation signal generator configured to generate a noise cancellation signal to reduce the ambient noise detected by the microphone, wherein
the baffle plate is provided with a diaphragm protecting portion located on the side from which the reproduction sound is radiated, the diaphragm protecting portion being provided with the sound emission holes to radiate the reproduction sound emitted from the speaker unit;
the diaphragm protecting portion includes a first portion facing the center dome and a second portion facing the sub-dome; and
an acoustic resistance member is provided only in an area of the baffle plate covering the sub-dome and controlling the reproduction sound radiated from the sub-dome, the acoustic resistance member being supported by the second portion of the diaphragm protecting portion.
2 . The noise-cancelling headphone device according to claim 1 , wherein the acoustic resistance member is arranged at a distance from the diaphragm.
3 . The noise-cancelling headphone device according to claim 1 , wherein the microphone is located on the side of the baffle plate where the reproduction sound is emitted through the acoustic resistance member.
4 . The noise-cancelling headphone device according to claim 1 , wherein the acoustic resistance member is formed of a non-woven fabric.
5 . The noise-cancelling headphone device according to claim 1 , wherein the acoustic resistance member is configured to reduce the reproduction sound radiated from the sub-dome in a high-frequency band above 1 kHz.
6 . The noise-cancelling headphone device according to claim 1 , wherein the microphone is located in a front cavity constituted by the baffle plate and an earpad located at a side of the baffle plate from which the reproduction sound is radiated.