Noise-canceling audio device including multiple vibration members
Noise-canceling audio devices may include a first vibration member, a second vibration member, and a microphone supported by a housing. A feedback, noise-cancelation circuit may be operatively connected to the microphone, the feedback, noise-cancelation circuit configured to generate a first portion of a modified audio signal by combining an audio signal with a noise-canceling signal generated in response to a signal from the microphone to at least partially cancel at least a portion of an audible response of the second vibration member. A feed-forward, noise-cancelation circuit may be operatively connected to the microphone, the feed-forward, noise-cancelation circuit configured to compare the signal from the microphone to a predetermined SPL profile and generate a second portion of the modified audio signal configured to at least partially cancel environmental noise, the feedback, noise cancelation circuit configured to output the modified audio signal only to the first vibration member.
1. A noise-canceling audio device, comprising:
a first vibration member supported at least partially within a housing;
a second vibration member supported at least partially within the housing;
a microphone supported by the housing;
a feedback, noise-cancelation circuit operatively connected to the microphone, the feedback, noise-cancelation circuit configured to generate a first portion of a modified audio signal by combining an audio signal from an audio input with a noise-canceling signal generated in response to a signal from the microphone to at least partially cancel at least a portion of an audible response of the second vibration member; and
a feed-forward, noise-cancelation circuit operatively connected to the microphone, the feed-forward, noise-cancelation circuit configured to compare the signal from the microphone to a predetermined sound pressure level (SPL), profile and generate a second portion of the modified audio signal configured to at least partially cancel environmental noise, the feedback, noise cancelation circuit configured to output the modified audio signal comprising the first portion and the second portion only to the first vibration member.
2. The noise-canceling audio device of claim 1 , wherein the feedback, noise-cancelation circuit is further configured to compare the signal from the microphone to the predetermined SPL profile and amplify the signal at one or more frequencies, reduce the signal at one or more frequencies, or amplify the signal at one or more frequencies and reduce the signal at one or more other frequencies to at least partially cancel the at least a portion of the audible response of the second vibration member.
3. The noise-canceling audio device of claim 1 , wherein the feedback, noise-cancelation circuit configured is configured to compare the signal from the microphone to the predetermined SPL profile only at frequencies between about 20 Hz and about 60 Hz.
4. The noise-canceling audio device of claim 1 , wherein the feed-forward, noise-cancelation circuit is configured to compare the signal from the microphone to the predetermined SPL profile and amplify the signal at one or more frequencies, reduce the signal at one or more frequencies, or amplify the signal at one or more frequencies and reduce the signal at one or more other frequencies to at least partially cancel the environmental noise.
5. The noise-canceling audio device of claim 4 , wherein the feedback, noise-cancelation circuit configured is configured to compare the signal from the microphone to the predetermined SPL profile only at frequencies between about 20 Hz and about 60 Hz.
6. The noise-canceling audio device of claim 1 , wherein the first vibration member comprises an audio driver and the second vibration member comprises a tactile vibrator.
7. The noise-canceling audio device of claim 6 , further comprising a low-pass filter operatively connected to the tactile vibrator and not to the audio driver, the low-pass filter configured to remove a treble component of the audio signal from passage to the tactile vibrator and pass a bass component of the audio signal to the tactile vibrator.
8. The noise-canceling audio device of claim 7 , further comprising a gain stage operatively connected between the audio input and the low-pass filter, the gain stage configured to increase a voltage of the audio signal from the audio input.
9. The noise-canceling audio device of claim 8 , wherein the gain stage comprises an operational amplifier.
10. The noise-canceling audio device of claim 8 , wherein the gain stage comprises a diode limiter configured to at least reduce clipping resulting from gain produced by the gain stage.
11. The noise-canceling audio device of claim 7 , further comprising an amplifier operatively connected between the low-pass filter and the tactile vibrator.
12. The noise-canceling audio device of claim 1 , wherein the microphone is located between the second vibration member and an ear of a user when the noise-canceling audio device is worn by the user.
13. The noise-canceling audio device of claim 12 , wherein a line passing through a geometric center of the first vibration member in a direction at least substantially parallel to a direction of intended movement of the first vibration member intersects with the microphone and the microphone is positioned on a side of the first vibration member proximate the ear of the user when the noise-canceling audio device is worn by the user.
14. The noise-canceling audio device of claim 12 , wherein the microphone comprises a microelectro-mechanical system (MEMS) microphone or an electret condenser microphone (ECM).
15. The noise-canceling audio device of claim 1 , wherein the microphone is exposed at an exterior of the housing.
16. The noise-canceling audio device of claim 1 , wherein the noise-canceling audio device is a headphone comprising a headband, and the audio input, and earcups supported proximate to ends of the headband, at least one of the earcups operatively connected to the audio input and comprising the housing, the first vibration member, the second vibration member supported, the microphone, the feedback, noise-cancelation circuit, and the feed-forward, noise-cancelation circuit.
17. The noise-canceling audio device of claim 16 , wherein the at least one of the earcups comprises:
a first acoustic cavity located proximate an ear of a user when the noise-canceling audio device is worn by the user, the first vibration member located in the first acoustic cavity;
a second acoustic cavity located adjacent to the first acoustic cavity and distal from the ear of the user when the noise-canceling audio device is worn by the user, the second vibration member located in the second acoustic cavity; and
a driver plate located between the first acoustic cavity and the second acoustic cavity, the driver plate including at least one passage extending between the first acoustic cavity and the second acoustic cavity, a greatest diameter of the at least one passage being between about 5% and about 10% of a greatest diameter of the housing.
18. The noise-canceling audio device of claim 17 , further comprising at least one port extending from the first acoustic cavity, through the housing of the earcups, to an exterior of the housing, a greatest diameter of the at least one port being between about 5% and about 10% of a greatest diameter of the housing.
19. The noise-canceling audio device of claim 17 , wherein the second vibration member comprises a tactile vibrator and further comprising a compressible material secured to the driver plate and positioned to delimit movement of the second vibration member of the tactile vibrator, the compressible material located on a side of the tactile vibrator proximate the ear of the user when the noise-canceling audio device is worn by the user.
20. The noise-canceling audio device of claim 1 , further comprising a status indicator configured to selectively indicate a status of the noise-canceling audio device.