Patent Description:
Headsets deliver sound to the ear. Certain headsets include earbuds placed into an ear canal opening. The earbuds may create a gentle seal between the earbud and the user's ear canal. Certain headsets cover an outer portion of the user's ears and may create a gentle seal between the headsets and an external surface of the user's body. Earbuds and over-the-hear headsets may inhibit a user from hearing sounds in the user's surroundings and may send a social cue that the user is unavailable for interaction with others. Audio devices that allow a user to more easily hear noise in the user's vicinity and provide an indication the user is available for interaction are desirable.

<CIT>, <CIT> and <CIT> disclose prior art audio devices arranged to provide some volume control.

The present invention relates to a method and a wearable open audio device according to the independent claims.

Open audio devices refer to audio devices that are not configured to physically obstruct a path between a user's ear canal and the outside world. Wearable open audio devices, also known as off-ear headphones, refer to wearable audio devices configured to be worn on or abutting an ear of a user, on a user's head, over the shoulders of the user, or otherwise on the user's body.

In-ear earbuds and over-the-ear headphones perform passive noise reduction by at least partially blocking or obstructing a path between the user's ear canal and the outside world. In contrast to earbuds or over-the-ear headphones, wearable open audio devices are not configured to perform this type of passive noise reduction as they do not block or obstruct the user's ear canal. This configuration allows a user to hear both sounds from the user's vicinity in addition to the audio output from the audio device. In some examples, the speaker outputting the sound may be positioned very close to or against the user's skin; however, leakage escaping into the environment may distract others. As the level of ambient noise changes, a user may manually adjust the volume to comfortably hear audio output from the device. Aspects of the present disclosure provide methods and apparatus to automatically adjust a sound pressure level of an audio device based on the ambient noise in an effort to minimize leakage and provide a seamless listening experience as the level of ambient noise changes.

<FIG> illustrates example components of an open audio device, in accordance with certain aspects of the present disclosure. According to an example, the audio device <NUM> is a wireless wearable open audio device. The audio device includes a memory and processor <NUM>, communication unit <NUM>, transceiver <NUM>, and audio output transducer or speaker <NUM>. The memory may include Read Only Memory (ROM), a Random Access Memory (RAM), and/or a flash ROM. The memory stores program code for controlling the memory and processor <NUM>. The memory and processor <NUM> control the operations of the wireless device <NUM>. Any or all of the components in <FIG> may be combined into multi-function components.

The processor <NUM> controls the general operation of the wireless device <NUM>. For example, the processor <NUM> performs process and control for audio and/or data communication. In addition to the general operation, the processor <NUM> is configured to automatically control the volume or SPL output by the audio device <NUM> based on the ambient noise as described herein. By adjusting the volume based on the ambient noise, the audio output by the audio device decreases or minimizes leakage that can be heard by others. Additionally, the automatic SPL adjustment provides a desirable listening experience for the user because the SPL of the audio output is automatically adjusted to be greater than the SPL of the detected ambient noise by at least a threshold amount. Accordingly, absent user interaction, the user may comfortably hear the audio output as a level of ambient noise changes.

The communication unit <NUM> facilitates a wireless connection with one or more other wireless devices. For example, the communication unit <NUM> may include one or more wireless protocol engines such as a Bluetooth engine. While Bluetooth is used as an example protocol, other communication protocols may also be used. Some examples include Bluetooth Low Energy (BLE), Near Field Communications (NFC), IEEE <NUM>, or other local area network (LAN) or personal area network (PAN) protocols.

The transceiver <NUM> transmits and receives information via one or more antennae to exchange information with one or more other wireless devices. According to aspects, one or more microphones <NUM> are configured to detect the ambient noise in the vicinity of the audio device, detect speech of a user wearing or proximate to the audio device, and convert the detected noise and/or speech into electrical signals. The transceiver <NUM> is not necessarily a distinct component.

The audio output transducer <NUM> may be also known as a driver or speaker. In some examples, more than one output transducer is used. The transducer converts electrical signals into sound and converts sound into electrical signals. The transducer is configured to output the audio signals having an automatically adjusted SPL.

<FIG> illustrates communication between certain modules of an example open audio device; however, aspects of the disclosure are not limited to the specific illustrated example. According to aspects, any module <NUM>-<NUM> is configured to communicate with any other module in the open audio device. In one example, all modules are connected to and communicate with each other.

<FIG> and <FIG> illustrate example form factors of a wearable open audio device, in accordance with aspects of the present disclosure. In <FIG>, an around-the-ear hook holds an audio transducer near an ear of a wearer, while in <FIG> an audio transducer is included in an eyeglass form factor. The example form factors in <FIG> and <FIG> are non-limiting; other form factors of a wearable open audio device are contemplated, including head, shoulder, or body-worn acoustic devices that include one or more acoustic drivers to produce sound without physically obstruct a path between a user's ear canal and the outside world. The wearable audio device of <FIG> and <FIG> include the one or more of the components illustrated in <FIG>. Both of the audio devices in <FIG> and <FIG> are configured to stay in place as the user moves his head. In <FIG>, the wearable audio device 200A is formed, in part, of a compliant material such that the audio device lightly clamps on the user's ear. In <FIG>, the wearable audio device 200B includes electronics 202B (such as those illustrated in <FIG>) contained at least partially within the frame of the audio eyeglasses 200B. In an example, the one or more speakers and microphones are located in or around the area 202B, proximate the temple region and above an ear of a user.

In some example, the microphone is placed so that it is in an acoustic null of the speaker output, which enhances acoustic isolation of the speaker output from the microphone. This helps to ensure the microphone is measuring the sounds of the ambient environment and not the audio output by the audio device. Accordingly, the microphone is able to determine the amount of ambient noise without an echo canceller while the speakers are outputting audio.

According to an example, one or more microphones are disposed proximate a temple region, on the bridge, and/or on the frame proximate the bottom of the lens of the audio eyeglasses 200B. According to an example, the frames of the acoustic audio eyeglasses 200B include a number of sound-emitting openings. The housing and its openings are constructed and arranged to achieve a desired delivery of audio to a particular location, for example, close to the user's ear. This helps to minimize leakage to the outside environment. A first front opening and a second rear opening radiate sound from a speaker to the environment outside the frames of the audio eyeglasses 202B in a manner that may be similar to an acoustic dipole. The audio eyeglasses 200B exhibit acoustic characteristics of an approximate dipole, where the effective dipole length is not fixed. Example configurations of audio devices configured with a variable dipole are described in <CIT> and <CIT>.

Examples of wearable audio devices are described in <CIT> and <CIT>.

<FIG> illustrates example operations <NUM> for controlling an SPL output of an audio device based on the ambient noise in accordance with aspects of the present disclosure. The audio device is an open audio device.

At <NUM>, the audio device outputs an audio signal via one or more speakers. At <NUM>, the audio device detects ambient noise. In an example, a microphone in the audio device detects the ambient noise. At <NUM>, the audio device compares an SPL of the audio signal with an SPL of the ambient noise. The ambient noise detected by the audio device changes by one or more of the audio device moving or varying ambient noise.

In an effort to adaptively adjust the audio output while minimizing leakage to others nearby the audio device, at <NUM>, the audio device automatically adjusts the SPL of the audio signal based, at least in part, on the comparison of the audio signal with the SPL of the ambient noise to generate an adjusted audio signal. In louder environments, a user of the audio device needs the audio output by the audio device to be louder and people in the vicinity of the audio device are less sensitive to leakage. When the ambient noise changes, for example to a quieter environment having a lower SPL, the user may not need the audio output to be as loud and people in the vicinity of the audio device in are more sensitive to leakage.

According to aspects, the audio device is configured with a first SPL threshold amount. When the absolute value of the difference between the SPL of the audio signal and the SPL of the ambient noise is greater than the first SPL threshold amount, the audio device is configured to, at <NUM>, automatically adjust the SPL of the audio signal.

According to aspects, the audio device is configured with a second SPL threshold amount. After the first SPL threshold is reached, the audio device is configured to adjust the SPL of the audio signal until the SPL of the adjusted audio signal exceeds the SPL of the detected ambient noise by the second SPL threshold amount. In some examples, the first SPL threshold amount is greater than the second SPL threshold amount. Thus, the audio device is configured to trigger automatically adjusting the SPL of the audio output when the absolute value of the difference between the SPL of the audio signal and the SPL of the ambient noise is within a first delta SPL amount, and the audio device adjusts the SPL of the audio output until the SPL of the audio output is greater than the SPL of the ambient environment by a second delta amount.

In an example, a user of a wearable audio device moves from a quieter environment, such as the user's home, to a louder environment, such as a busy street. Instead of manually increasing the volume to comfortably hear the audio output as the user walks outside along the busy street, the audio device determines the SPL difference between the ambient noise and the audio output is greater than the first SPL threshold amount. In response, the audio device boosts the volume of the audio output until the SPL of the adjusted audio output is greater than the ambient noise by a second SPL threshold amount.

According to an example, a different boost in SPL is applied to different frequency bands. In an example, the boost is applied to bass, mid-range, and/or treble frequency bands. In an example, bass frequency bands refer to lower frequencies that are below <NUM>, mid-range frequency bands refer to frequencies between <NUM> and <NUM>, and treble frequency bands refer to higher frequencies above <NUM>.

According to aspects, the SPL boost applied to lower bass band frequencies is greater than the SPL boost applied to mid-range frequencies and the SPL boost applied to mid-range frequencies is greater than the SPL boost applied to treble frequencies.

Continuing with the example, the user walks into a quiet office space from the busy street. Instead of manually decreasing the volume to comfortably hear the audio and minimize disruption to others, the audio device determines the SPL of the ambient environment is greater than the SPL of the audio output by more than the first SPL threshold amount. In response, the audio device decreases the SPL of the audio output until the SPL of the adjusted audio output is greater than the SPL ambient environment by the second SPL threshold amount. According to aspects, a different adjustment in SPL is applied to different frequency bands. In an example, the SPL adjustment is applied to bass, mid-range, and/or treble frequency bands. According to aspects, a larger decrease in SPL is applied to lower bass band frequencies as compared to mid-range frequencies and a larger decrease in SPL is applied to mid-range frequencies as compared to treble frequencies. In an example, a smaller decrease in SPL is applied to higher frequencies of the audio signal.

Table <NUM> provides example SPL boost values in dB applied to music audio based on the frequency range. The music has a constant SPL of <NUM> dB estimated at the user's ear. The ambient noise increases from <NUM> dB to <NUM> dB in increments of <NUM> dB. Because there is no or substantially no feedback path, the SPL boost applied per frequency range does not result in an increase (or substantial increase) in estimated music SPL at the user's ear.

The increase in or decrease in SPL is independently controlled for each frequency range. As shown in Table <NUM>, the SPL of the bass band frequencies are boosted more than the SPL of the mid-range frequencies, and the SPL of the mid-rage frequencies are boosted more than the SPL of the treble frequencies. Correspondingly, when the ambient noise decreases, for example, from <NUM> dB to <NUM> dB, the SPL of the bass band frequencies are decreased more than the SPL of the mid-range frequencies, and the SPL of the mid-range frequencies are decreased more than the SPL of the treble frequencies.

At <NUM>, the audio device outputs the adjusted audio signal. As described above, the adjusted audio signal may have an SPL that is greater than or less than the SPL of the audio signal output at <NUM>.

As described above, the sound pressure of the audio signal is continuously adjusted to be greater than the SPL of the ambient noise by at least the second SPL threshold amount. According to aspects, after <NUM>, the method continues to <NUM> to re-detect the ambient noise. At <NUM>, the audio device compares the SPL of the adjusted audio signal and an SPL of the re-detected ambient noise. At <NUM>, the audio device further automatically adjusts the SPL of the adjusted audio signal based on the comparison of the SPL of the adjusted audio signal and the SPL of the re-detected ambient noise to generate a further adjusted audio signal. At <NUM>, the audio device outputs the further adjusted audio signal.

In certain open-ear audio devices, the microphone detects ambient noise as well as the audio output of the audio device. An echo canceller may be used to cancel the audio signal output from the open-ear audio device from the signals detected by the microphone. According to aspects, an echo canceller is not needed in the audio device configured to perform automatic SPL adjustment based on the ambient noise. Instead, the one or more microphones are located within the audio device so that it is positioned in an acoustic null of the speaker, such that the one or more microphones substantially do not detect the audio signal and the adjusted audio signal output by the audio device while detecting the ambient noise.

In an example, due to the location and configuration of the one or more microphones and speakers, the audio signals are output by the speakers in substantially a first direction and the microphone detects signals outside of the first direction. By substantially not detecting audio signals output by the speakers, the microphones primarily detect only the ambient noise. Accordingly, the audio device may not need to perform resource-intensive calculations using, for example, an echo canceller, to cancel the output of the audio device from the signal detected by the microphone. An example speaker that outputs sound substantially in a first direction is described in <CIT> and <CIT>.

Absent the techniques described herein, a user would need to adjust the volume of the audio output based on changes in the ambient environment, and/or a device would require a resource-intensive echo canceller to enable the microphone to accurately detect the ambient noise level. The automatic SPL adjustment provides a comfortable, more-seamless listening experience despite changes in the user's ambient environment. Thus, a user may listen to audio output that is automatically adjusted to accommodate the user's setting. Further, the user may not recognize any changes in the SPL of the audio signal output by the audio device. In addition, the position of the one or more microphones and the configuration of the speaker permit more accurate and efficient automatic SPL adjustment, requiring a lower overall use of processing resources and therefore improving the battery life of the audio device.

In the preceding, reference is made to aspects presented in this disclosure. However, the scope of the present disclosure is not limited to specific described aspects. Aspects of the present disclosure may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a "component," "circuit," "module" or "system. " Furthermore, aspects of the present disclosure may take the form of a computer program product embodied in one or more computer readable medium(s) having computer readable program code embodied thereon.

More specific examples a computer readable storage medium include: an electrical connection having one or more wires, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the current context, a computer readable storage medium may be any tangible medium that can contain, or store a program.

Claim 1:
A method performed by a wearable open audio device (<NUM>) including one of a head, shoulder, or body-worn acoustic device that includes a microphone (<NUM>) and one or more acoustic drivers (<NUM>) to produce sound without physically obstructing a path between a user's ear canal and an outside world, the method comprising:
outputting (<NUM>) an audio signal by means of the one or more acoustic drivers;
detecting (<NUM>) ambient noise by means of the microphone;
comparing (<NUM>) a sound pressure level of the audio signal with a sound pressure level of the ambient noise;
automatically adjusting (<NUM>) the sound pressure level of the audio signal based, at least in part, on the comparison to generate an adjusted audio signal;
outputting (<NUM>) the adjusted audio signal by means of the one or more acoustic drivers; wherein:
comparing the sound pressure level of the audio signal with the sound pressure level of the ambient noise comprises determining the absolute value of the difference between the sound pressure level of the audio signal and the sound pressure level of the detected ambient noise is greater than a first sound pressure threshold amount,
responsive to the determination, adjusting the sound pressure level of the audio signal, and wherein:
adjusting the sound pressure level of the audio signal comprises: adjusting the sound pressure level of the audio signal until the sound pressure level of the adjusted audio signal exceeds the sound pressure level of the detected ambient noise by more than a second sound pressure threshold amount, wherein the first and second sound pressure threshold amounts are different.