Maximum a Posteriori Binary Mask Estimation for Underdetermined Source Separation Using Smoothed Posteriors

Sound source separation has become a topic of intensive research in the last years. The research effort has been specially relevant for the underdetermined case, where a considerable number of sparse methods working in the time-frequency (T-F) domain have appeared. In this context, although binary masking seems to be a preferred choice for source demixing, the estimated masks differ substantially from the ideal ones. This paper proposes a maximum a posteriori (MAP) framework for binary mask estimation. To this end, class-conditional source probabilities according to the observed mixing parameters are modeled via ratios of dependent Cauchy distributions while source priors are iteratively calculated from the observed histograms. Moreover, spatially smoothed posteriors in the T-F domain are proposed to avoid noisy estimates, showing that the estimated masks are closer to the ideal ones in terms of objective performance measures.This work was supported by the Spanish Ministry of Science and Innovation under project TEC2009-14414-C03-01. The associate editor coordinating the review of this manuscript and approving it for publication was Prof. Jingdong Chen.Cobos Serrano, M.; López Monfort, JJ. (2012). Maximum a Posteriori Binary Mask Estimation for Underdetermined Source Separation Using Smoothed Posteriors. IEEE Transactions on Audio, Speech and Language Processing. 20(7):2059-2064. doi:10.1109/TASL.2012.2195654S2059206420

Compensating first reflections in non-anechoic head-related transfer function measurements

[EN] Personalized Head-Related Transfer Functions (HRTFs) are needed as part of the binaural sound individ- ualization process in order to provide a high-quality immersive experience for a specific user. Signal processing methods for performing HRTF measurements in non-anechoic conditions are of high interest to avoid the complex and inconvenient access to anechoic facilities. Non-anechoic HRTF measurements capture the effect of room reflections, which should be correctly identified and eliminated to obtain HRTFs estimates comparable to ones acquired in an anechoic setup. This paper proposes a sub-band frequency-dependent processing method for reflection suppression in non-anechoic HRTF signals. Array processing techniques based on Plane Wave Decomposition (PWD) are adopted as an essential part of the solution for low frequency ranges, whereas the higher frequencies are easily handled by means of time-crop windowing methods. The formulation of the model, extraction of parameters and evaluation of the method are described in detail. In addition, a validation case study is presented showing the suppression of reflections from an HRTF measured in a real system. The results confirm that the method allows to obtain processed HRTFs comparable to those acquired in anechoic conditions.This work has received funding from the Spanish Ministry of Science, Innovation and Universities, through projects RTI2018097045-B-C21 and RTI2018-097045-B-C22, and Generalitat Valenciana under the AICO/2020/154 project grant.López Monfort, JJ.; Gutierrez-Parera, P.; Cobos, M. (2022). Compensating first reflections in non-anechoic head-related transfer function measurements. Applied Acoustics. 188:1-13. https://doi.org/10.1016/j.apacoust.2021.10852311318

On the distance perception in spatial audio system: a comparison between Wave-Field Synthesis and Panning Systems

Creating a realistic distance perception by means of spatial audio reproduction systems is not an easy task. Cues such as the ratio between the direct signal and the level of reverberation have been traditionally employed in stereo and surround systems. With the introduction of advanced spatial audio systems such as Wave Field Synthesis (WFS), it is possible to synthesize within the whole listening area the correct wavefront curvature produced by a virtual source located at a given distance. Some previous studies suggest that this curvature can be an additional cue for the listener to extrapolate distance. In this work, a subjective perceptual test has been carried out to compare the capabilities of WFS and Vector Base Amplitude Panning (VBAP) to reproduce accurately sound distances. Different variables were studied; type of sound, listening angle and reverberation at different distances. The analysis of the collected data suggests that WFS is better at reproducing distances than panning systems.Gutiérrez Parera, P.; López Monfort, JJ.; Aguilera Martí, E. (2014). On the distance perception in spatial audio system: a comparison between Wave-Field Synthesis and Panning Systems. Waves. 6:51-59. http://hdl.handle.net/10251/57870S5159

Computer-based detection and classification of flaws in citrus fruits

[EN] In this paper, a system for quality control in citrus fruits is presented. In current citrus manufacturing industries, calliper and color are successfully used for the automatic classification of fruits using vision systems. However, the detection of flaws in the citrus surface is carried out by means of human inspection. In this work, a computer vision system capable of detecting defects in the citrus peel and also classifying the type of flaw is presented. First, a review of citrus illnesses has been carried out in order to build a database of digitalized oranges classified by the kind of fault, which is used as a training set. The segmentation of faulty zones is performed by applying the Sobel gradient to the image. Afterwards, color and texture features of the flaw are extracted considering different color spaces, some of them related to high order statistics. Several techniques have been employed for classification purposes: Euler distance to a prototype, to the nearest neighbor and k-nearest neighbors. Additionally, a three layer neural network has been tested and compared, obtaining promising results.López Monfort, JJ.; Cobos Serrano, M.; Aguilera Martí, E. (2011). Computer-based detection and classification of flaws in citrus fruits. Neural Computing and Applications. 20(7):975-981. doi:10.1007/s00521-010-0396-2S975981207Blasco J, Aleixos J, Molto E (2007) Computer vision detection of peel defects in citrus by means of a region oriented segmentation. J Food Eng 81:535–543Blasco J, Aleixos N, Gomez J, Molto E (2007) Citrus sorting by identification of the most common defects using multispectral computer vision. J Food Eng 83:384–391Bryson AE, Ho YC (1969) Applied optimal control: optimization, estimation, and control. Xerox College Publishing, Lexington, MAConners RWea (1983) Identifying and locating surface defects in wood. IEEE Trans Pattern Anal Mach Intell 5:573–583Diaz R, Gil L, Serrano C, Blasco M, Molto E, Blasco J (2004) Comparison of three algorithms in the classification of table olives by means of computer vision. J Food Eng 61:101–107Douglas DH, Peucker TK (1973) Algorithm for the reduction of the number of points required to represent a line or its caricature. The Can Cartogr 10(2):112–122Du CJ, Sun DW (2005) Comparison of three methods for classification of pizza topping using different colour space transformations. J Food Eng 68:277–287Kolesnikov A (2003) Efficient algorithms for vectorization and polygonal approximation. Ph.D. thesis, University of Joensuu, FinlandMolto E (1997) A computer vision system for inspecting citrus, peaches and apples. In: Proceedings of VII national symposium on pattern recognition and image analysis. Sabadell, Spain, pp 121–126Muir AY, Porteus RL, Wastie RL (1982) Experiments in the detection of incipient diseases in potato tubers by optical methods. J Agric Eng Res 27:131–138Q Li (2002) Computer vision based system for apple surface defect detection. computer and electronics in agriculture. Comput Electron Agric 36:215–223Ruiz LA, Molto E, Juste F, Pla F, Valiente R (1996) Location and characterization of the stem–calyx area on oranges by computer vision. J Agric Eng Res 64:165–172Tan TSC, Kittler J (1994) Colour texture analysis using colour histogram. IEEE Proc Vis Image Signal Process 141:403–412Wen Z, Tao Y (1999) Building a rule-based machine-vision system for defect inspection on apple sorting and packing lines. Expert Syst Appl 16:307–31

Perception of nonlinear distortion on emulation of frequency responses of headphones

[EN] The equalization of headphones can force transducers to work in a non-linear condition, producing non-linear distortion. Depending on the headphone model and the reproduction level, that distortion can be audible. In this study, headphones of diverse quality and price were compelled to emulate the same target frequency response and the non-linear distortion was measured. A Diagonal Volterra model was used to simulate the different headphones with and without distortion. A perceptual test was carried out to determine the level of reproduction above which non-linear distortion is perceived for each headphone model. High correlation has been found between the level of detected distortion and retail prices of headphones.The Spanish Ministry of Economy, Industry and Competitiveness supported this work under the project TEC2015-68076-R and Grant No. BES-2013-065034.Gutierrez-Parera, P.; López Monfort, JJ. (2018). Perception of nonlinear distortion on emulation of frequency responses of headphones. The Journal of the Acoustical Society of America. 143(4):2085-2088. https://doi.org/10.1121/1.5031030S20852088143

Speaker Localization and Detection in Videoconferencing Environments Using a Modified SRP-PHAT Algorithm

[EN] The Steered Response Power - Phase Transform (SRP-PHAT) algorithm has been shown to be one of the most robust sound source localization approaches operating in noisy and reverberant environments. However, its practical implementation is usually based on a costly fine grid-search procedure, making the computational cost of the method a real issue. In this paper, we introduce an effective strategy which performs a full exploration of the sampled space rather than computing the SRP at discrete spatial positions, increasing its robustness and allowing for a coarser spatial grid that reduces the computational cost required in a practical implementation. The modified SRP-PHAT functional has been successfully implemented in a real time speaker localization system for multiparticipant videoconferencing environments. Moreover, a localization-based speech-non speech frame discriminator is presented.This work was supported by the Ministry of Education and Science under the project TEC2009-14414-C03-01.Martí Guerola, A.; Cobos Serrano, M.; Aguilera Martí, E.; López Monfort, JJ. (2011). Speaker Localization and Detection in Videoconferencing Environments Using a Modified SRP-PHAT Algorithm. Waves. 3:40-47. http://hdl.handle.net/10251/57648S4047

Subjective quality assessment of multichannel audio accompanied with video in representative broadcasting genres

Immersive broadcasting applications have received a lot of attention in the last years. In this context, the development of advanced HDTV and 3DTV formats is being successfully adopted by the consumer market, having a strong impact in the way that traditional broadcasting contents are displayed to final users. Together with the above advances in video technology, multichannel spatial audio has also experienced a considerable impulse within the audiovisual industry. However, the need for specific production tools and loudspeaker setups corresponding to multiple competing audio formats seems to be an important factor affecting their adoption by the consumer community. Moreover, it is well-known that the perceived audio quality is highly influenced by the reproduction context, where the existing multimodal interaction between audio and video plays a very important role. This paper presents a formal evaluation of the perceived sound quality provided by several spatial audio formats accompanied with video in the context of television broadcasting. Stereo, advanced surround formats and 3D Binaural sound are evaluated considering a set of representative broadcasting contents (sports, movies, music and animation) to assess their impact on the perceptual attributes contemplated within the international recommendations.The Spanish Ministry of Economy and Competitiveness and FEDER supported this work under the projects TEC2012-37945- 1091 C02- 01/02.Cobos Serrano, M.; López Monfort, JJ.; Navarro Ruiz, JM.; Ramos Peinado, G. (2015). Subjective quality assessment of multichannel audio accompanied with video in representative broadcasting genres. Multimedia Systems. 21(4):363-379. doi:10.1007/s00530-013-0340-2S363379214Apostolopoulos, J., Chou, P., Culbertson, B., Kalker, T., Trott, M., Wee, S.: The road to immersive communication. Proc. IEEE 100(4), 974–990 (2012). doi: 10.1109/JPROC.2011.2182069Huang, Y., Chen, J., Benesty, J.: Immersive audio schemes. IEEE Signal Process. Mag. 28(1), 20–32 (2011). doi: 10.1109/MSP.2010.938754Huynh-Thu, Q., Barkowsky, M., Le Callet, P.: The importance of visual attention in improving the 3D-TV viewing experience: overview and new perspectives. IEEE Trans. Broadcast. 57(2), 421–431 (2011). doi: 10.1109/TBC.2011.2128250Wang, K., Barkowsky, M., Brunnstrom, K., Sjostrom, M., Cousseau, R., Le Callet, P.: Perceived 3D TV transmission quality assessment: multi-laboratory results using absolute category rating on quality of experience scale. IEEE Trans. Broadcast. PP(99), 1 (2012). doi: 10.1109/TBC.2012.2191031Zhang, L., Vazquez, C., Knorr, S.: 3D-TV content creation: automatic 2D-to-3D video conversion. IEEE Trans. Broadcast. 57(2), 372–383 (2011). doi: 10.1109/TBC.2011.2122930Kyriakakis, C., Tsakalides, P., Holman, T.: Surrounded by sound. IEEE Signal Process. Mag. 16(1), 55–66 (1999). doi: 10.1109/79.743868Rumsey, F.: Spatial Audio. Focal Press, Waltham (2001)Eargle, J.M. (eds): AES Anthology: Stereophonic Techniques. Publications of the Audio Engineering Society, New York (1986)Holman, T.: 5.1 Surround Sound: Up and Running, 2nd edn. Focal Press, Waltham (2007)Steinke, G.: High definition surround sound with accompanying HD picture. In: Proceedings of the International Tonmeister Symposium. Vabaria (2005)Breebaart, J., Faller, C.: Spatial Audio Processing: MPEG Surround and Other Applications. Wiley, Chichester (2007)Holman, T.: Sound for Film and Television, 3rd edn. Focal Press, Waltham (2010)Theile, G.: HDTV sound systems: how many channels? In: Proceedings of the AES 9th International Conference. Detroit, Michigan (1991)Strohmeier, D., Jumisko-Pyykkö S.: How does my 3D video sound like?—impact of loudspeaker set-ups on audiovisual quality on mid-sized autostereoscopic display. In: Proceedings of the 3DTV Conference (3DTV-CON’08). Istanbul, Turkey (2008)Zielinski, S., Rumsey, F., Bech, S.: Subjective audio quality trade-offs in consumer multichannel audio-visual delivery systems. Part I: Effects of high frequency limitation. In: Proceedings of the AES 112th Convention. Munich, Germany (2002)Bech, S., Zacharov, N.: Perceptual audio evaluation—theory, method and application. John Wiley & Sons, Chichester (2006)Brotherton, M.D., Huynh-Thu, Q., Hands, D.S., Brunnstrom, K.: Subjective multimedia quality assessment. IEICE Trans. Fundam. Electron. Commun. Comput. Sci. E89-A(11), 2920–2932 (2006)Jumisko-Pyykkö, S., Hakkinen, J., Nyman, G.: Experienced quality factors—qualitative evaluation approach to audiovisual quality. In: Proceedings of 19th SPIE Annual Symposium on Electronic Imaging. San Jose, California, USA (2007)Recommendation ITU-R BS.775-1: Multichannel Stereophonic Sound System With and Without Accompanying Picture. International Telecommunications Union, Geneva (1994)Recommendation ITU-T P.911: Subjective Audiovisual Quality Assessment Methods for Multimedia Applications. International Telecommunications Union, Geneva (1998)EBU Tech 3276-E: Supplement 1—Listening Conditions for the Assessment of Sound Programme Material: Multichannel Sound. International Telecommunications Union, Geneva (2004)Theile, G.: On the naturalness of two-channel stereo sound. J. Audio Eng. Soc. 39, 761–767 (1991)Dolby 7.1 home theater speaker guide. http://www.dolby.com/ . Accessed 05 July 2012Silzle, A., George, S., Habets, E.A.P., Bachmann, T.: Investigation on the quality of 3D sound reproduction. In: Proceedings of the International Conference on Spatial Audio (ICSA 2011). Detmold, Germany (2011)Hamasaki, K., Hiyama, K., Okumura, R.: The 22.2 multichannel sound system and its application. In: Proceedings of the 118th AES Convention. Barcelona, Spain (2005)Theile, G., Wittek, H.: Principles in surround recordings with height. In: Proceedings of the 130th AES Convention. London, UK (2011)Dolby ProLogic IIz. http://www.dolby.com/ . Accessed 05 July 2012Kim, S., Lee, Y.W., Pulkki, V.: New 10.2-channel vertical surround system (10.2-VSS); comparison study of perceived audio quality in various multichannel sound systems with height loudspeakers. In: Proceedings of the 129th AES Convention. San Francisco, USA (2010)Algazi, V.R., Duda, R.Q.: Headphone-based spatial sound. IEEE Signal Process. Mag. 28(1), 33–42 (2011)Moller, H., Sorensen, M.F., Jensen, C.B., Hammershoi, D.: Binaural technique: do we need individual recordings? J. Audio Eng. Soc. 44, 451–468 (1996)Jumisko-Pyykkö, S., Weitzel, M., Strohmeier, D.: Designing for user experience: what to expect from mobile 3D TV and video? In: Proceedings of the 1st International Conference on Designing Interactive User Experiences for TV and Video (UXTV ’08). Mountain View, CA, USA (2008)Goldstein, E.B.: Sensation and Perception. Wadsworth Publishing, Belmont (2002)Jumisko-Pyykkö, S.: User-Centered Quality of Experience and its Evaluation Methods for Mobile Television. Ph.D. thesis, Tampere University of Technology (2011)Hollier, M.P., Rimell, A.N., Hands, D.S., Voelcker, R.M.: Multi-modal perception. BT Technol. J. 17(1), 35–46 (1999)Hands, D.S.: A basic multimedia quality model. IEEE Trans. Multimed. 6(6), 806–816 (2004)Beerends, J.G., de Caluwe, F.E.: The influence of video quality on perceived audio quality and vice versa. J. Audio Eng. Soc. 47(5), 355–362 (1999)You, J., Reiter, U., Hannuksela, M.M., Gabbouj, M., Perkins, A.: Perceptual-based quality assessment for audio-visual services: a survey. Signal Process. Image Commun. 25, 482–501 (2010)Jones, C., Atkinson, D.J.: Development of opinion-based audiovisual quality models for desktop video-teleconferencing. In: Proceedings of the 6th International Workshop on Quality of Services (IWQoS 98). Napa Valley, CA (1998)Jumisko-Pyykkö, S., Strohmeier, D.: Cognitive styles and visual quality. In: Proceedings of SPIE 8667, Multimedia Content and Mobile Devices (2013)Nixon, N.F., Spitz, L.: The diction of auditory visual desynchrony. Perception 9, 719–721 (1980)Belmudez, B., Moeller, S., Lewcio, B., Raake, A., Mehmood, A.: Audio and video channel impact on perceived audio-visual quality in different interactive contexts. In: IEEE International Workshop on Multimedia Signal Processing, 2009. (MMSP ’09) (2009)Reiter, U.: Subjective assessment of the optimum number of loudspeaker channels in audio-visual applications using large screens. In: Proceedings of the 28th AES International Conference (2006)Steinke, G.: Surround-sound: Relations of listening and viewing configurations. In: Proceedings of the 116th AES Convention. Berlin, Germany. Paper 6019 (2004)Recommendation ITU-R BS.1116-1: Methods for Subjective Assessment of Small Impairments in Audio Systems Including Multichannel Sound Systems (1994)Recommendation ITU-R: 710-4: Subjective Assessment Methods for Image Quality in High-Definition Television. International Telecommunications Union, Geneva (1998)Recommendation ITU-R 500: Methodology for the Subjective Assessment of the Quality of Television Pictures. International Telecommunications Union, Geneva (2002)Recommendation ITU-R BS.1284-1: General Methods for the Subjective Assessment of Sound Quality. International Telecommunications Union, Geneva (2003)Recommendation ITU-R BT.1128-2: Subjective Assessment of Conventional Television Systems. International Telecommunications Union, Geneva (1997)Drewery, J.O., Salmon, R.A.: Tests of Visual Acuity to Determine the Resolution Required of a Television Transmission System. BBC R& D White Paper. WHP, 092 (2004)Recommendation ITU-R BS.1283: Subjective Assessment of Sound Quality—A Guide to Existing Recommendations. International Telecommunications Union, Geneva (1997)Recommendation ITU-R BS.1285: Pre-Selection Methods for the Subjective Assessment of Small Impairments in Audio Systems. International Telecommunications Union, Geneva (1997)Recommendation ITU-R BS.1286: Methods for the Subjective Assessment of Audio Systems with Accompanying Picture. International Telecommunications Union, Geneva (1998)Hershey, J., Movellan, J.: Audio-vision: using audio-visual synchrony to locate sounds. In: Advances in Neural Information Processing Systems, pp. 813–819. MIT Press, Cambridge (1999)Thurston, L.L.: A law of comparative judgment. Psychol. Rev. 101(2), 266–270 (1994)One TV Year in the World (2011 issue). Tech. rep., Mediametrie (2011)Neuraltm Upmix by DTS User Guide. DTS Document Number 9302J70400B (2010)Nuendo 3: Operation Manual. Steinberg Media Technologies, GmbH (2005)Pulkki, V.: Virtual sound source positioning using vector base amplitude panning. J. Audio Eng. Soc. 45(6), 456–566 (1997)Dolby headphone webpage. http://www.dolby.com/us/en/consumer/technology/home-theater/dolby-headphone.html (2012). Accessed 07 May 2012H3D Binaural Spatializer Manual. Longcat Audio Technologies SARL (2011)Blauert, J.: Spatial hearing. In: The Psychophysics of Human Sound Localization. MIT Press, Cambridge (1996)Kramer, C.Y.: Extension of multiple range tests to group means with unequal numbers of replications. Biometrics 12, 307–310 (1956)Mosteller, F.: Remarks on the method of paired comparisons: the least squares solution assuming equal standard deviations and equal correlations. Psychometrika 16(1), 3–9 (1951)Tsukida, K., Gupta, M.R.: How to Analyze Paired Comparison Data. Tech. rep., Department of Electrical Engineering, University of Washington (2011

A modified SRP-PHAT functional for robust real-time sound source localization with scalable spatial sampling

The Steered Response Power – Phase Transform (SRP-PHAT) algorithm has been shown to be one of the most robust sound source localization approaches operating in noisy and reverberant environments. However, its practical implementation is usually based on a costly fine grid-search procedure, making the computational cost of the method a real issue. In this letter, we introduce an effective strategy that extends the conventional SRP-PHAT functional with the aim of considering the volume surrounding the discrete locations of the spatial grid. As a result, the modified functional performs a full exploration of the sampled space rather than computing the SRP at discrete spatial positions, increasing its robustness and allowing for a coarser spatial grid. To this end, the Generalized Cross-Correlation (GCC) function corresponding to each microphone pair must be properly accumulated according to the defined microphone setup. Experiments carried out under different acoustic conditions confirm the validity of the proposed approach.Manuscript received September 06, 2010; revised October 22, 2010; accepted October 27, 2010. Date of publication November 11, 2010; date of current version December 16, 2010. This work was suported by the The Spanish Ministry of Science and Innovation supported this work under the project TEC2009-14414-C03-01. The associate editor coordinating the review of this manuscript and approving it for publication was Dr. Constantine L. Kotropoulos.Cobos Serrano, M.; Martí Guerola, A.; López Monfort, JJ. (2011). A modified SRP-PHAT functional for robust real-time sound source localization with scalable spatial sampling. IEEE Signal Processing Letters. 18:71-74. doi:10.1109/LSP.2010.2091502S71741

An Immersive Multi-Party Conferencing System for Mobile Devices Using 3D Binaural Audio

[EN] The use of mobile telephony, along with the widespread of smartphones in the consumer market, is gradually displacing traditional telephony. Fixed-line telephone conference calls have been widely employed for carrying out distributed meetings around the world in the last decades. However, the powerful characteristics brought by modern mobile devices and data networks allow for new conferencing schemes based on immersive communication, one the fields having major commercial and technical interest within the telecommunications industry today. In this context, adding spatial audio features into conventional conferencing systems is a natural way of creating a realistic communication environment. In fact, the human auditory system takes advantage of spatial audio cues to locate, separate and understand multiple speakers when they talk simultaneously. As a result, speech intelligibility is significantly improved if the speakers are simulated to be spatially distributed. This paper describes the development of a new immersive multi-party conference call service for mobile devices (smartphones and tablets) that substantially improves the identification and intelligibility of the participants. Headphone-based audio reproduction and binaural sound processing algorithms allow the user to locate the different speakers within a virtual meeting room. Moreover, the use of a large touch screen helps the user to identify and remember the participants taking part in the conference, with the possibility of changing their spatial location in an interactive way.This work has been partially supported by the government of Spain grant TEC-2009-14414-C03-01 and by the new technologies department of TelefónicaAguilera Martí, E.; López Monfort, JJ.; Cobos Serrano, M.; Macià Pina, L.; Martí Guerola, A. (2012). An Immersive Multi-Party Conferencing System for Mobile Devices Using 3D Binaural Audio. Waves. 4:5-14. http://hdl.handle.net/10251/57918S514

Impact of the Content of Fatty Acids of Oral Fat Tolerance Tests on Postprandial Triglyceridemia: Systematic Review and Meta-Analysis

Whether the content of saturated (SFA), monounsaturated (MUFA), and polyunsaturated fatty acids (PUFA) could differently influence postprandial triglycerides (TG) is unknown. We examined possible differences in the postprandial TG response to fat tolerance tests (FTTs), in which SFA or unsaturated fatty acids were used. Crossover clinical trials investigating the effects of FTTs containing SFA and unsaturated fats on postprandial triglyceridemia in databases from 1994 until 2016 were searched. Of 356 studies, 338 were excluded and 18 were considered. TG net incremental areas under the curve were calculated using time-points or changes from baseline. Pooled effects of standardized mean differences and I2 test were used. Results: In 12 studies, responses to SFA versus PUFA meals, and in 16 studies versus MUFA meals were compared. Over 4 hours, no differences between SFA and unsaturated fats were observed. Over 8 hours a lower response to PUFA (SMD −2.28; 95%CI −4.16, −0.41) and a trend to lower response to MUFA (SMD −0.89, 95%CI −1.82, 0.04) were detected. FTTs shorter than 8 hours may not be sufficient to differentiate postprandial TG after challenges with distinct fatty acids. Clinical significance of different postprandial TG responses on cardiovascular risk in the long-term deserves investigation