# US 2014/0153728 A1 · Delay measurement apparatus and delay measurement method for network music session > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0153728 A1 - Document ID: US20140153728A1 - Status: Published application - Kind: A1 - Application number: 14/091,231 - Filed: 2013-11-26 - Published: 2014-06-05 - Earliest claimed: 2012-11-30 - Assignees: Yamaha Corporation - Applicants: Yamaha Corporation - Inventors: Takahiro HARA - Web page: https://patentgrep.com/patent/US20140153728A1 ## CPC - H04R 29/00: Monitoring arrangements; Testing arrangements {(for hearing aids H04R25/30; detection of loudspeaker connection H04R5/04; sound-field adaptation dependent on speaker detection H04S7/308)} - H04L 43/0852: Delays - 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) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract In this system, a terminal A retrieves terminal's input delay time Tia from input of an audio signal to start of transmission of the audio signal, transmission delay time Tn from the start of transmission of the audio signal to reception of the audio signal by a partner terminal B, partner's reception buffering delay time Tbfb from reception of the audio signal to output of the audio signal by a reception buffer portion BFb of the partner terminal B, and partner's output delay time Tob from input of the audio signal to output of the audio signal by an audio reproduction portion DRob of the partner terminal B. The terminal A then sums up these delay times to determine input/output delay time Ttab from the input of the audio signal by the terminal A to the output of the audio signal by the audio reproduction portion DRob of the partner terminal B. ## Claims ### Claim 1 A delay measurement apparatus for network music session, the delay measurement apparatus being provided on a session terminal that performs a network music session with a partner session terminal connected with the session terminal through a communication network so that the session terminal communicates with the partner session terminal, the delay measurement apparatus comprising: a terminal's input delay retrieval portion for retrieving terminal's input delay time from input of an audio signal to start of transmission of the audio signal on the terminal; a transmission delay retrieval portion for retrieving transmission delay time from the terminal to the partner terminal, the transmission delay time being taken from the start of transmission of the audio signal by the session terminal to reception of the audio signal by the partner session terminal; a partner's reception buffering delay retrieval portion for retrieving partner's reception buffering delay time from reception of the audio signal by a reception buffer portion of the partner session terminal to input of the audio signal to an audio reproduction portion of the partner session terminal; a partner's output delay retrieval portion for retrieving partner's output delay time from input of the audio signal from the reception buffer portion to output of the audio signal by the audio reproduction portion on the partner session terminal; and an input/output delay time determination portion for summing up the terminal's input delay time retrieved by the terminal's input delay retrieval portion, the transmission delay time from the terminal to the partner terminal retrieved by the transmission delay retrieval portion, the partner's reception buffering delay time retrieved by the partner's reception buffering delay retrieval portion, and the partner's output delay time retrieved by the partner's output delay retrieval portion, and determining input/output delay time from the input of the audio signal on the terminal to the output of the audio signal from the audio reproduction portion of the partner session terminal. ### Claim 2 (depends on 1) The delay measurement apparatus for network music session according to claim 1, wherein the transmission delay retrieval portion retrieves updated transmission delay time from the terminal to the partner terminal by using measurement packets which are transmitted and received at regular intervals between the partner session terminal to monitor time at which the measurement packets are transmitted and received. ### Claim 3 (depends on 1) The delay measurement apparatus for network music session according to claim 1, wherein a buffer size of the reception buffer portion of the partner session terminal is changed automatically or is changed in accordance with user's manipulation; and the partner's reception buffering delay retrieval portion retrieves updated partner's reception buffering delay time regularly calculated in accordance with the buffer size from the partner session terminal. ### Claim 4 (depends on 1) The delay measurement apparatus for network music session according to claim 1, wherein the terminal's input delay time includes delay time caused by A/D conversion and encoding of the input audio signal by an audio output portion. ### Claim 5 (depends on 1) The delay measurement apparatus for network music session according to claim 1, wherein the partner's output delay time includes delay time caused by decoding and D/A conversion of the input audio signal by the audio reproduction portion of the partner session terminal; and the partner's output delay retrieval portion retrieves the partner's output delay time from the partner session terminal in response to establishment of connection with the partner session terminal. ### Claim 6 A delay measurement method for network music session, the method being executed on a session terminal that performs a network music session with a partner session terminal connected with the session terminal through a communication network so that the session terminal communicates with the partner session terminal, the method comprising the steps of: a terminal's input delay retrieval step of retrieving terminal's input delay time from input of an audio signal to start of transmission of the audio signal on the terminal; a partner's output delay retrieval step of retrieving partner's output delay time from input of the audio signal from a reception buffer portion to output of the audio signal by an audio reproduction portion on the partner session terminal; a partner's reception buffering delay retrieval step of retrieving partner's reception buffering delay time from reception of the audio signal by the reception buffer portion of the partner session terminal to input of the audio signal to the audio reproduction portion of the partner session terminal; a transmission delay retrieval step of retrieving transmission delay time from the terminal to the partner terminal, the transmission delay time being taken from the start of transmission of the audio signal by the session terminal to reception of the audio signal by the partner session terminal; and an input/output delay time determination step of summing up the terminal's input delay time retrieved at the terminal's input delay retrieval step, the partner's output delay time retrieved at the partner's output delay retrieval step, the partner's reception buffering delay time retrieved at the partner's reception buffering delay retrieval step, and the transmission delay time from the terminal to the partner terminal retrieved at the transmission delay retrieval step, and determining input/output delay time from the input of the audio signal on the terminal to the output of the audio signal from the audio reproduction portion of the partner session terminal. ### Claim 7 (depends on 6) The delay measurement method for network music session according to claim 6, wherein the transmission delay retrieval step retrieves updated transmission delay time from the terminal to the partner terminal by using measurement packets which are transmitted and received at regular intervals between the partner session terminal to monitor time at which the measurement packets are transmitted and received. ### Claim 8 (depends on 6) The delay measurement method for network music session according to claim 6, wherein a buffer size of the reception buffer portion of the partner session terminal is changed automatically or is changed in accordance with user's manipulation; and the partner's reception buffering delay retrieval step retrieves updated partner's reception buffering delay time regularly calculated in accordance with the buffer size from the partner session terminal. ### Claim 9 (depends on 6) The delay measurement method for network music session according to claim 6, wherein the terminal's input delay time includes delay time caused by A/D conversion and encoding of the input audio signal by an audio output portion. ### Claim 10 (depends on 6) The delay measurement method for network music session according to claim 6, wherein the partner's output delay time includes delay time caused by decoding and D/A conversion of the input audio signal by the audio reproduction portion of the partner session terminal; and the partner's output delay retrieval step retrieves the partner's output delay time from the partner session terminal in response to establishment of connection with the partner session terminal. ### Claim 11 A computer-readable medium storing a delay measurement computer program for network music session, the computer program being executed on a session terminal that performs a network music session with a partner session terminal connected with the session terminal through a communication network so that the session terminal communicates with the partner session terminal, the computer program comprising the steps of: a terminal's input delay retrieval step of retrieving terminal's input delay time from input of an audio signal to start of transmission of the audio signal on the terminal; a partner's output delay retrieval step of retrieving partner's output delay time from input of the audio signal from a reception buffer portion to output of the audio signal by an audio reproduction portion on the partner session terminal; a partner's reception buffering delay retrieval step of retrieving partner's reception buffering delay time from reception of the audio signal by the reception buffer portion of the partner session terminal to input of the audio signal to the audio reproduction portion of the partner session terminal; a transmission delay retrieval step of retrieving transmission delay time from the terminal to the partner terminal, the transmission delay time being taken from the start of transmission of the audio signal by the session terminal to reception of the audio signal by the partner session terminal; and an input/output delay time determination step of summing up the terminal's input delay time retrieved at the terminal's input delay retrieval step, the partner's output delay time retrieved at the partner's output delay retrieval step, the partner's reception buffering delay time retrieved at the partner's reception buffering delay retrieval step, and the transmission delay time from the terminal to the partner terminal retrieved at the transmission delay retrieval step, and determining input/output delay time from the input of the audio signal on the terminal to the output of the audio signal from the audio reproduction portion of the partner session terminal.