# US 10,455,080 B2 · Methods and devices for improvements relating to voice quality estimation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,455,080 B2 - Document ID: US10455080B2 - Status: Granted - Kind: B2 - Application number: 15/539,101 - Filed: 2015-12-23 - Published: 2018-01-11 - Granted: 2019-10-22 - Earliest claimed: 2014-12-23 - Assignees: Dolby Laboratories Licensing Corporation - Applicants: Dolby Laboratories Licensing Corporation - Inventors: Doh-Suk Kim; Shen Huang - Web page: https://patentgrep.com/patent/US10455080B2 ## CPC - H04M 3/2236: {Quality of speech transmission monitoring} - H04L 43/04: Processing captured monitoring data, e.g. for logfile generation - H04L 43/0829: Packet loss - G10L 25/60: for measuring the quality of voice signals - H04M: TELEPHONIC COMMUNICATION (circuits for controlling other apparatus via a telephone cable and not involving telephone switching apparatus G08) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - G10L: SPEECH ANALYSIS TECHNIQUES OR SPEECH SYNTHESIS; SPEECH RECOGNITION; SPEECH OR VOICE PROCESSING TECHNIQUES; SPEECH OR AUDIO CODING OR DECODING ## Abstract This disclosure falls into the field of voice communication systems, more specifically it is related to the field of voice quality estimation in a packet based voice communication system. In particular the disclosure provides a method and device for 5 reducing a prediction error of the voice quality estimation by considering the content of lost packets. Furthermore, this disclosure provides a method and device which uses a voice quality estimating algorithm to calculate the voice quality estimate based on an input which is switchable between a first and a second input mode. ## Claims ### Claim 1 A method for modifying a statistical metric relating to lost voice packets in a packet based voice communication system, comprising the steps of: receiving data comprising a sequence of encoded voice packets transmitted from one or more end-points in the voice communication system, wherein encoded voice packets transmitted from the one or more end-points comprises the received sequence of encoded voice packets and one or more lost voice packets which were lost during the transmission from the one or more end-points or discarded due to latency and/or jitter in the transmission, the data comprising a signal indicating a perceptual importance of each of the encoded voice packets transmitted from the one or more end-points; calculating, based on the received sequence of encoded voice packets, a statistical metric relating to the lost voice packets; and modifying the statistical metric based on the perceptual importance of the lost voice packets, so as to reduce a prediction error of a voice quality estimate when using the modified statistical metric, in place of the statistical metric, as input to a voice quality estimating algorithm configured to receive and base its estimating on the statistical metric. ### Claim 2 (depends on 1) The method according to claim 1, wherein the statistical metric includes at least one of: a packet loss rate, PLR, which is the number of lost voice packets in relation to a total number of transmitted voice packets, and a burstiness factor, BF, which is one minus a number of groups of consecutive lost voice packets in relation to the number of lost voice packets. ### Claim 3 (depends on 2) The method according to claim 2, wherein the step of modifying the statistical metric based on a perceptual importance of the lost voice packets comprises linear or non-linear mapping of the PLR to a perceptual PLR, linear or non-linear mapping of the BF to a perceptual BF, or both. ### Claim 4 (depends on 1) The method according to claim 1, wherein the step of modifying the statistical metric comprises weighting the lost voice packets according to their perceptual importance. ### Claim 5 (depends on 1) The method according to claim 1, wherein the statistical metric relates to groups of consecutive lost voice packets, each group comprising one or more lost voice packets, wherein in the step of calculating the statistical metrics, each group of consecutive lost voice packets is weighted based on the number of consecutive lost voice packets in the group, and wherein, in the step of modifying the statistical metric, each group is further weighted based on the perceptual importance of the lost voice packets in the group. ### Claim 6 (depends on 1) The method according to claim 1, wherein the perceptual importance for a lost voice packet is estimated based on perceptual importance of voice packets in the sequence of encoded voice packets which are adjacent to the packets that were lost during the transmission from the one or more end-points or discarded due to latency and/or jitter of the transmission. ### Claim 7 (depends on 1) The method according to claim 1, wherein each voice packet in the received sequence of encoded voice packets comprises a separate bit indicating the perceptual importance of the voice packet. ### Claim 8 (depends on 1) The method according to claim 1, wherein the signal indicating the perceptual importance includes a respective bit in each voice packet in the received sequence of encoded voice packets. ### Claim 9 (depends on 1) The method according to claim 1, further comprising the step of: partially decoding at least some of the received encoded voice packets in order to estimate perceptual importance of the lost voice packets. ### Claim 10 (depends on 1) A non-transitory computer-readable storage medium with instructions adapted to carry out the method of claim 1 when executed by a device having processing capability. ### Claim 11 (depends on 1) A non-transitory computer-readable storage medium with instructions adapted to carry out the method of claim 1 when executed by a device having processing capability. ### Claim 12 A device for modifying a statistical metric relating to lost voice packets in a packet based voice communication system, the device comprising: a receiving stage configured to receive data comprising a sequence of encoded voice packets transmitted from one or more end-points in the voice communication system, wherein encoded voice packets transmitted from the one or more end-points comprises the received sequence of encoded voice packets and one or more lost voice packets which were lost during the transmission from the one or more end-points or discarded due to latency and/or jitter in the transmission, the data comprising a signal indicating a perceptual importance of each of the encoded voice packets transmitted from the one or more end-points; a calculating stage configured to calculate, based on the received sequence of encoded voice packets, a statistical metric relating to a number of lost voice packets; and a perceptual transformation stage configured to modify the statistical metric based on the perceptual importance of the lost voice packets, so as to reduce a prediction error of a voice quality estimate when using the modified statistical metric as input to a voice quality estimating algorithm.