# US 2020/0401365 A1 · Ultrasonic transmission for presence detection

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- Number: US 2020/0401365 A1
- Document ID: US20200401365A1
- Status: Published application
- Kind: A1
- Application number: 17/008,372
- Filed: 2020-08-31
- Published: 2020-12-24
- Earliest claimed: 2019-02-28
- Assignees: Sonos, Inc.
- Applicants: Sonos, Inc.
- Inventors: Dayn Wilberding; Youjin Nam; Tadeo T. Toulis; Cole Harris; Patrick Devine; Nicholas A.J. Millington; Jodi Vautrin; Maria-Jose Ramos; Richard Bannon; Michael Sheldon; Ted Lin; Ron Kuper; Kirsten Lewis; Jake Harwood; Jonathan Herbst; Daniel Jones; Henry Sia
- Web page: https://patentgrep.com/patent/US20200401365A1

## CPC

- G06F 3/165: {Management of the audio stream, e.g. setting of volume, audio stream path}
- G01S 11/14: using ultrasonic, sonic or infrasonic waves
- G06F 3/162: {Interface to dedicated audio devices, e.g. audio drivers, interface to CODECs}
- G10L 25/51: for comparison or discrimination
- H04R 3/12: for distributing signals to two or more loudspeakers {(specially adapted for hearing aids H04R25/407)}
- H04R 27/00: Public address systems (circuits for preventing acoustic reaction H04R3/02; circuits for distributing signals to loudspeakers H04R3/12; {monitoring or testing arrangements for public address systems H04R29/007}; amplifiers H03F)
- G01S 5/16: using electromagnetic waves other than radio waves
- G01S 5/18: using ultrasonic, sonic or infrasonic waves
- G01S 19/14: specially adapted for specific applications
- H04R 2205/021: Aspects relating to docking-station type assemblies to obtain an acoustical effect, e.g. the type of connection to external loudspeakers or housings, frequency improvement
- H04R 2227/003: Digital PA systems using, e.g. LAN or internet
- H04R 2227/005: Audio distribution systems for home, i.e. multi-room use
- H04R 2420/05: Detection of connection of loudspeakers or headphones to amplifiers
- H04R 2420/07: Applications of wireless loudspeakers or wireless microphones
- H04R 2430/01: Aspects of volume control, not necessarily automatic, in sound systems
- G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N)
- G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G10L: SPEECH ANALYSIS TECHNIQUES OR SPEECH SYNTHESIS; SPEECH RECOGNITION; SPEECH OR VOICE PROCESSING TECHNIQUES; SPEECH OR AUDIO CODING OR DECODING
- H04R: LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS (producing sounds with frequency not determined by supply frequency G10K)

## Abstract

Examples described herein relate to transitioning a playback session between portable playback devices such as “smart” headphones, earbuds, and handheld speakers with playback devices of a zone-based media playback system. Exemplary techniques facilitate continuity of playback when transitioning between locations (e.g., from at home to on-the-go or vice versa) or between listening paradigms (e.g., personal or out-loud playback of audio content). An example implementation includes detecting a swap trigger, determining the source playback device(s) and target playback device(s), and performing a playback session swap between the source playback device(s) and target playback device(s).

## Claims

### Claim 1

A portable playback device comprising:
one or more microphones;
one or more batteries;
one or more processors;
a non-transitory, computer-readable medium storing instructions that, when executed by the one or more processors, cause the portable playback device to perform functions comprising:
receiving an indication to perform presence detection of one or more playback devices;
transmitting one or more messages instructing the one or more playback devices to transmit respective audio signals for presence detection;
after transmitting the one or more messages, receiving, via a first microphone, a first audio signal;
determining a time-frequency representation of the first audio signal;
based on the time-frequency representation of the first audio signal and data indicating respective reference audio signals, determining that the audio signal comprises a superposition of a second audio signal transmitted by a first playback device and a third audio signal transmitted by a second playback device;
based on the audio signal, determining a first magnitude associated with the second audio signal and a second magnitude associated with the third audio signal;
based on determining that the first magnitude is greater than the second magnitude, determining that the first playback device is arranged in closer proximity than the second playback device to the portable playback device; and
transitioning a playback session between the portable playback device and the first playback device.

### Claim 2 (depends on 1)

The portable playback device of claim 1, wherein receiving the indication to perform presence detection of one or more playback devices comprises:
receiving data representing a first playback session swap input; and
wherein transmitting the one or more messages instructing the one or more playback devices to transmit respective audio signals for presence detection comprises:
based on receiving the data representing the first playback session swap input, transmitting the one or more messages instructing the one or more playback devices to transmit the respective audio signals for presence detection.

### Claim 3 (depends on 1)

The portable playback device of claim 1, wherein receiving the indication to perform presence detection of one or more playback devices comprises:
detecting a user interaction with the portable playback device; and
based on the user interaction, determining a predicted swap command state, and
wherein transmitting one or more messages instructing one or more playback devices to transmit respective audio signals for presence detection comprises:
based on determining the predicted swap command state, transmitting the one or more messages instructing the one or more playback devices to transmit the respective audio signals for presence detection.

### Claim 4 (depends on 3)

The portable playback device of claim 3, wherein detecting the user interaction with the portable playback device comprises:
determining that an interaction has occurred on a control interface of the portable playback device.

### Claim 5 (depends on 1)

The portable playback device of claim 1, wherein the functions further comprise:
determining available presence detection techniques of the one or more playback devices; and
based on the available presence detection techniques, selecting an audio chirp technique as a presence detection technique.

### Claim 6 (depends on 1)

The portable playback playback device of claim 1, wherein the functions further comprise:
connecting to a network;
after connecting to the network, receiving state information of the one or more playback devices connected to the network; and
based on the state information, determining that the first playback device and the second playback device are swap-capable playback devices.

### Claim 7 (depends on 1)

The portable playback device of claim 1, wherein transmitting the one or more messages instructing the one or more playback devices to transmit respective audio signals for presence detection comprises:
transmitting a message to all of the one or more playback devices to transmit respective audio signals for presence detection.

### Claim 8

A non-transitory, computer-readable medium storing instructions that, when executed by one or more processors, cause a portable playback device to perform functions comprising:
receiving an indication to perform presence detection of one or more playback devices;
transmitting one or more messages instructing the one or more playback devices to transmit respective audio signals for presence detection;
after transmitting the one or more messages, receiving, via a first microphone, a first audio signal;
determining a time-frequency representation of the first audio signal;
based on the time-frequency representation of the first audio signal and data indicating respective reference audio signals, determining that the audio signal comprises a superposition of a second audio signal transmitted by a first playback device and a third audio signal transmitted by a second playback device;
based on the audio signal, determining a first magnitude associated with the second audio signal and a second magnitude associated with the third audio signal;
based on determining that the first magnitude is greater than the second magnitude, determining that the first playback device is arranged in closer proximity than the second playback device to the portable playback device; and
transitioning a playback session between the portable playback device and the first playback device.

### Claim 9 (depends on 8)

The non-transitory, computer-readable medium of claim 8, wherein receiving the indication to perform presence detection of one or more playback devices comprises:
receiving data representing a first playback session swap input; and
wherein transmitting the one or more messages instructing one or more playback devices to transmit respective audio signals for presence detection comprises:
based on receiving the data representing the first playback session swap input, transmitting the one or more messages instructing the one or more playback devices to transmit the respective audio signals for presence detection.

### Claim 10 (depends on 8)

The non-transitory, computer-readable medium of claim 8, wherein receiving an indication to perform presence detection of one or more playback devices comprises:
detecting a user interaction with the portable playback device; and
based on the user interaction, determining a predicted swap command state, and
wherein transmitting one or more messages instructing one or more playback devices to transmit respective audio signals for presence detection comprises:
based on determining the predicted swap command state, transmitting the one or more messages instructing the one or more playback devices to transmit the respective audio signals for presence detection.

### Claim 11 (depends on 10)

The non-transitory, computer-readable medium of claim 10, wherein detecting the user interaction with the portable playback device comprises:
determining that an interaction has occurred on a control interface of the portable playback device.

### Claim 12 (depends on 8)

The non-transitory, computer-readable medium of claim 8, wherein the functions further comprise:
determining available presence detection techniques of the one or more playback devices; and
based on the available presence detection techniques, selecting an audio chirp technique as a presence detection technique.

### Claim 13 (depends on 8)

The non-transitory, computer-readable medium of claim 8, wherein the functions further comprise:
connecting to a network;
after connecting to the network, receiving state information of the one or more playback devices connected to the network; and
based on the state information, determining that the first playback device and the second playback device are swap-capable playback devices.

### Claim 14 (depends on 8)

The non-transitory, computer-readable medium of claim 8, wherein transmitting one or more messages instructing the one or more playback devices to transmit respective audio signals for presence detection comprises:
transmitting a message to all of the one or more playback devices to transmit respective audio signals for presence detection.

### Claim 15

A media playback system, comprising:
a portable playback device;
a first playback device;
a second playback device;
one or more non-transitory, computer-readable media storing instructions that when executed by one or more processors cause the media playback system to perform functions comprising:
receiving, via the portable playback device, an indication to perform presence detection of one or more playback devices;
transmitting, via the portable playback device, one or more messages instructing the one or more playback devices to transmit respective audio signals for presence detection;
transmitting, via the first playback device, a first audio signal;
transmitting, via the second playback device, a second audio signal;
after transmitting the one or more messages, receiving, via the portable playback device, a third audio signal comprising the first audio signal and the second audio signal;
determining, via the portable playback device, a time-frequency representation of the third audio signal;
based on the time-frequency representation of the third audio signal and data indicating respective reference audio signals, determining, via the portable playback device, that the audio signal comprises a superposition of a second audio signal transmitted by the first playback device and a third audio signal transmitted by the second playback device;
based on the third audio signal, determining, via the portable playback device, a first magnitude associated with the second audio signal and a second magnitude associated with the third audio signal;
based on determining that the first magnitude is greater than the second magnitude, determining, via the portable playback device, that the first playback device is arranged in closer proximity than the second playback device to the portable playback device; and
transitioning, via the portable playback device, a playback session between the portable playback device and the first playback device.

### Claim 16 (depends on 15)

The media playback system of claim 15, wherein receiving, via the portable playback device, the indication to perform presence detection of one or more playback devices comprises:
receiving data representing a first playback session swap input; and
wherein transmitting, via the portable playback device, one or more messages instructing one or more playback devices to transmit respective audio signals for presence detection comprises:
based on receiving the data representing the first playback session swap input, transmitting the one or more messages instructing the one or more playback devices to transmit the respective audio signals for presence detection.

### Claim 17 (depends on 15)

The media playback system of claim 15, wherein receiving, via the portable playback device, an indication to perform presence detection of one or more playback devices comprises:
detecting a user interaction with the portable playback device; and
based on the user interaction, determining a predicted swap command state, and
wherein transmitting, via the portable playback device, one or more messages instructing one or more playback devices to transmit respective audio signals for presence detection comprises:
based on determining the predicted swap command state, transmitting the one or more messages instructing the one or more playback devices to transmit the respective audio signals for presence detection.

### Claim 18 (depends on 17)

The media playback system of claim 17, wherein detecting, via the portable playback device, the user interaction with the portable playback device comprises:
determining that an interaction has occurred on a control interface of the portable playback device.

### Claim 19 (depends on 15)

The media playback system of claim 15, wherein the functions further comprise:
determining, via the portable playback device, available presence detection techniques of the one or more playback devices; and
based on the available presence detection techniques, selecting, via the portable playback device, an audio chirp technique as a presence detection technique.

### Claim 20 (depends on 15)

The media playback system of claim 15, wherein the first audio signal and the second audio signal are in a frequency range of 18-20 kHz.