Details

Published: 21 April 2016

SDM Toolbox v1.0 published

The newly published toolbox is available at Matlab File Exchange as well as directly in .zip format at https://mediatech.aalto.fi/~tervos/SDMtoolbox.zip .

SDMtoolbox is a collection of matlab functions and scripts for spatial room impulse response analysis and synthesis using Spatial Decomposition method [1]. 

Visualization of the spatial room impulse response is implemented as in [2]. Other examples of the visualization have been shown for example in [3],[4] and [5]. Synthesis of the spatial room impulse response is implemented as described in [4]. Binaural synthesis follows the method in [6]. 

The toolbox processes spatial room impulse responses, measured with a microphone array. The microphone array has to be specified as a.micLocs = microphone locations in Cartesian coordinates [numberOfMics 3] and in the order [x,y,z].

The spatial impulse response should be presented in the same order as the microphone locations IR : [N numberOfMics]

For auralization, a loudspeaker array must be defined with s.lspLocs = loudspeaker in Spherical coordinates [numberOfLoudSpeaker 3] The order is Azimuth in degrees, Elevation in degrees, and Radius in meters.

There are several standard default loudspeaker setups, e.g., 5.1, in createSynthesisStruct.m, which you can use directly.

Example use cases for analysis, visualization, synthesis, and reproduction with different loudspeaker arrays or binaurally with headphones are found in:

demoCustomSetups.m 

demoDefaultSetups.m 

demoBinauralRendering.m 

To run these examples, type 

> demoCustomSetups 

> demoDefaultSetups 

> demoBinauralRendering 

in your Matlab command prompt.

This version has been tested with Matlab R2015b and R2014b. Some functions are not available in older versions. For example, parula.m and websave.m are not included before R2014b.

The demos are using examples files, which you can also directly download by copy-pasting these links to your browser 

https://mediatech.aalto.fi/~tervos/IR_living_room.mat 

https://mediatech.aalto.fi/~tervos/IR_another_living_room.mat 

https://mediatech.aalto.fi/~tervos/IR_home_control_room.mat 

https://mediatech.aalto.fi/~tervos/demoJAES/samples/Song1_CR1.mp3

References:

[1] S. Tervo, J. Pätynen, A. Kuusinen, T. Lokki "Spatial decomposition method for room impulse responses", Journal of the Audio Engineering Society, vol. 61, no. 1/2, pp. 16-27, 2013 

[2] J. Pätynen, S. Tervo, T. Lokki, "Analysis of concert hall acoustics via visualizations of time-frequency and spatiotemporal responses", In J. Acoustical Society of America, vol. 133, no. 2, pp. 842-857, 2013. 

[3] S. Tervo, J. Saarelma, J. Pätynen, P. Laukkanen, I. Huhtakallio, "Spatial analysis of the acoustics of rock clubs and nightclubs", In the IOA Auditorium Acoustics, Paris, France, pp. 551-558, 2015 

[4] S. Tervo, J. Pätynen, N. Kaplanis, M. Lydolf, S. Bech, and T. Lokki "Spatial Analysis and Synthesis of Car Audio System and Car Cabin Acoustics with a Compact Microphone Array", Journal of the Audio Engineering Society 63 (11), 914-925, 2014 

[5] P. Laukkanen "Evaluation of Studio Control Room Acoustics with Spatial Impulse Responses and Auralization", Master's thesis, Aalto University, 2014 

[6] J. Pätynen, S. Tervo, and T. Lokki, "Amplitude panning decreases spectral brightness with concert hall auralizations", In Proc. 55th Audio Eng. Soc. conference Helsinki, Finland, Aug. 27-29 2014.

Details

Published: 26 October 2015

The IOA Auditorium Acoustics conference is the major conference on concert hall acoustics this year. In the end of October all concert hall acoustics researchers and consultant will gather to Paris to see the new Philharmonie de Paris and to share the latest research results. We have strong contribution with seven presentations, which are the following:

1. Sakari Tervo, Jukka Pätynen, Perttu Laukkanen, Ilkka Huhtakallio, and Jukka Saarelma: Spatial analysis of the acoustics of rock clubs and nightclubs
2. Jukka Pätynen, Sakari Tervo, and Tapio Lokki: Subjective impact of concert hall acoustics
3. Henrik Möller, Jukka Pätynen, Sakari Tervo, and Tapio Lokki: Practical application and analysis of full orchestra spatial impulse responses in an opera house
4. Henna Tahvanainen and Tapio Lokki: Bass in concert halls — recent studies on the seat-dip effect
5. Jukka Saarelma: Sound field visualization using the finite-difference time-domain method and measured spatial room impulse responses
6. Antti Kuusinen and Tapio Lokki: Auditory distance perception in concert halls and the origins of acoustic intimacy
7. Tapio Lokki, Jukka Pätynen, Sakari Tervo, Antti Kuusinen, Henna Tahvanainen, and Aki Haapaniemi: The secret of the Musikverein and other shoebox concert halls 

We are really looking forward a great conference in Paris!

Check the whole program here!

References

@inproceedings{ter15ioa,
	address = "Paris, France",
	author = {S. Tervo and J. Saarelma and J. P{\"a}tynen and I. Huhtakallio and P. Laukkanen},
	booktitle = "The 9th International Conference on Auditorium Acoustics",
	date-added = "2015-11-12 14:05:23 +0000",
	date-modified = "2015-11-12 14:05:23 +0000",
	month = "October 29-31",
	title = "Spatial analysis of the acoustics of rock clubs and nightclubs",
	url = "https://mediatech.aalto.fi/~ktlokki/Publs/p79_2015.pdf",
	year = 2015,
	bdsk-url-1 = "https://mediatech.aalto.fi/~ktlokki/Publs/p79_2015.pdf"
}

@inproceedings{pat15ioa,
	address = "Paris, France",
	author = {J. P\"{a}tynen and S. Tervo and T. Lokki},
	booktitle = "The 9th International Conference on Auditorium Acoustics",
	date-added = "2015-11-12 14:01:47 +0000",
	date-modified = "2015-11-12 14:01:47 +0000",
	keywords = "Concert hall acoustics",
	month = "October 29-31",
	title = "Subjective impact of concert hall acoustics",
	url = "https://mediatech.aalto.fi/~ktlokki/Publs/p20_2015.pdf",
	year = 2015,
	bdsk-url-1 = "https://mediatech.aalto.fi/~ktlokki/Publs/p20_2015.pdf"
}

@inproceedings{mol15ioa,
	address = "Paris, France",
	author = {H. M\"{o}ller and J. P\"{a}tynen and S. Tervo and T. Lokki},
	booktitle = "The 9th International Conference on Auditorium Acoustics",
	date-added = "2015-11-12 13:55:23 +0000",
	date-modified = "2015-11-12 13:59:41 +0000",
	keywords = "Concert hall acoustics",
	month = "October 29-31",
	title = "Practical application and analysis of full orchestra spatial impulse responses in an opera house",
	url = "https://mediatech.aalto.fi/~ktlokki/Publs/p6_2015.pdf",
	year = 2015
}

@inproceedings{tah15ioa,
	address = "Paris, France",
	author = "H. Tahvanainen and T. Lokki",
	booktitle = "The 9th International Conference on Auditorium Acoustics",
	date-added = "2015-11-12 13:55:23 +0000",
	date-modified = "2015-11-12 14:00:37 +0000",
	keywords = "Concert hall acoustics",
	month = "October 29-31",
	title = "Bass in concert halls -- recent studies on the seat-dip effect",
	url = "https://mediatech.aalto.fi/~ktlokki/Publs/p78_2015.pdf",
	year = 2015
}

@inproceedings{saa15ioa,
	address = "Paris, France",
	author = "J. Saarelma and G. Greco",
	booktitle = "The 9th International Conference on Auditorium Acoustics",
	date-added = "2015-11-12 13:55:23 +0000",
	date-modified = "2015-11-12 14:07:06 +0000",
	month = "October 29-31",
	title = "Sound field visualization using the finite-difference time-domain method and measured spatial room impulse responses",
	url = "https://mediatech.aalto.fi/~ktlokki/Publs/p68_2015.pdf",
	year = 2015
}

@inproceedings{kuu15ioa,
	address = "Paris, France",
	author = "A. Kuusinen and T. Lokki",
	booktitle = "The 9th International Conference on Auditorium Acoustics",
	date-added = "2015-11-12 13:55:23 +0000",
	date-modified = "2015-11-12 13:57:20 +0000",
	keywords = "Concert hall acoustics",
	month = "October 29-31",
	title = "Auditory distance perception in concert halls and the origins of acoustic intimacy",
	url = "https://mediatech.aalto.fi/~ktlokki/Publs/p18_2015.pdf",
	year = 2015
}

@inproceedings{lok15ioa,
	address = "Paris, France",
	author = {T. Lokki and J. P\"{a}tynen and S. Tervo and A. Kuusinen and H. Tahvanainen and A. Haapaniemi},
	booktitle = "The 9th International Conference on Auditorium Acoustics",
	date-added = "2015-11-12 13:55:23 +0000",
	date-modified = "2015-11-12 13:59:16 +0000",
	keywords = "Concert hall acoustics",
	month = "October 29-31",
	title = "The secret of the Musikverein and other shoebox concert halls",
	url = "https://mediatech.aalto.fi/~ktlokki/Publs/p25_2015.pdf",
	year = 2015
}

Details

Published: 03 February 2015

Details

Published: 03 March 2014

The importance of early lateral reflections to good concert hall acoustics has been known for decades by researchers and practitioners of room acoustics. Earlier, they have been mainly believed to widen the perceived overall sound image and bring the perceived distance of the sound closer. A new finding by the Virtual Acoustics research group shows that the orchestra dynamics cause different range of auditory excitation depending on the concert hall acoustics. Moreover, the results suggest that the responsiveness of the concert hall to music dynamics is higher in classical shoebox-type halls.

The research, just published in the Proceedings of The National Academy of Sciences of The United States of America (PNAS), combines studies from three aspects: 1) Dynamic spectrum of a symphony orchestra; 2) Sensitivity of directional hearing, and 3) Spatial analysis of concert hall measurements. 

1) The dynamic changes in music is one of the key components in expressivity. When the orchestra is playing very softly, the high frequencies (harmonic overtones) are only barely excited. When music is played more forcefully, the entire timbre of the orchestra becomes brighter as the the high frequencies are excited a lot. By comparing the spectra in different dynamics, we have learned that in the overall orchestra sound the high frequencies are emphasized much more than lower frequencies near the note fundamentals with increased dynamics.

2) The shape of the human head and ears modify the sound depending on which direction the sound is arriving from. This filtering effect is widely known as head-related transfer functions (HRTF). The directional sensitiviy increases towards high frequencies, so that at around 2kHz sound coming from the side are emphasized with regard to sound coming from the front.

3) The concert hall geometry influences greatly to the directions of sound reflections. In late 2012, a group of six researchers completed a comprehensive measurement tour in ten European concert halls. With spatio-temporal analysis on the measured shoebox-type halls, it is typical that distinct early reflections arrive from the sides in the lateral plane. Reflections in other types of halls are more scarce, and arrive from less optimal directions.

A combination of these three aspects yield a situation, where in low dynamics the instruments do not radiate much high frequencies. Hence, the high-frequency directional hearing is much neglected. However, with stronger playing the high frequencies come along, and the reflection paths and directional hearing are emphasized. If the early reflections arrive from the sides, they enhance the high frequencies with respect to the direct sound.

Generally the classical shoebox-design concert halls, such as the Vienna Musikverein, Amsterdam Concertgebouw, and Boston Symphony hall, are considered as the best. Although the Boston hall is not included in the measurements, it is expected to show results comparable to the acclaimed European halls. Earlier studies have presented results where lateral reflections with more high frequencies increase the subjective preference. Since the shoebox geometry is shown to increase the hall's responsiveness to musical dynamics, thus expressivity, the results presented in the article can potentially explain the general preference for the classical shoebox concert halls.


J. Pätynen, S. Tervo, P. Robinson, and T. Lokki: "Concert halls with strong lateral reflections enhance musical dynamics". Proc. Natl. Acad. Soc., vol. 111, no. 9, March 2014.

Article URL:  http://www.pnas.org/cgi/doi/10.1073/pnas.1319976111