*5.2.1. The quantitative test*

A set of multiple choice questions about several audio sequences were administered to a group of people (17 in total). In this test, some urban acoustic features were analysed. This first test, as shown in **Table 2**, was given once the recordings and acoustic analysis had been carried out. The test had two objectives: to characterise people's perception and knowledge of Evaluation between Virtual Acoustic Model and Real Acoustic Scenarios for Urban Representation http://dx.doi.org/10.5772/intechopen.78330 57


**Table 2.** Description and definition of the options in the quantitative test.

**5.1. Usability evaluation**

meet all a user's needs [49].

We could define usability as a general quality that indicates the suitability for a specific pur-

This term is linked with the development of products (which could be systems, technologies, tools, applications or devices) that can be easy to learn, effective and enjoyable in the user's experience. Nevertheless, usability can be considered another factor in a wider process called the acceptability of a system. Thus, acceptability defines whether a system is good enough to

In ISO/IEC 9126, usability is defined as "software product capability to be understood, learned, used and attractive for the user, when it is used under specific conditions." However, usability is not limited to computer systems. It is a concept that can be applied to any element

In addition, in ISO/IEC 9241-11, the guidelines for the usability of a particular product are described. Here, usability is defined as "the level in which a product can be used by particular users in order to reach specified goals with effectivity, efficiency and satisfaction in a particular context of use." In our research, the effectivity of a system is related with its goals, efficiency is related with the performance of the used resources to reach the goals, and satisfaction is related with its acceptability and commodity [50]. This definition is based on the concept of *quality in use*, and describes how the user does particular tasks in particular environments in an effective way [51]. For Bevan, the quality of use, measured in terms of efficiency, efficacy and satisfaction, is not only determined by the product, but also by the context (kind of users, tasks of the users and physical environment). Therefore, the usability, understood as the quality in use of a product is the interaction between a user and a product while a task is being

In our study, usability defines the general quality, indicating the suitability for educational purposes of an immersive scenario. In a similar line as [52], the goal is to evaluate the student motivation before and after the use of such technologies. Users are asked to evaluate the quality of the soundscape representation in this scenario. Both visual and acoustic data have a direct impact on the perception of the space and the realism of this representation is the focus of the evaluation.

Two kinds of experiments were carried out with architecture students. The first group of experiments considered a quantitative approach to the evaluation, whereas the second group

A set of multiple choice questions about several audio sequences were administered to a group of people (17 in total). In this test, some urban acoustic features were analysed. This first test, as shown in **Table 2**, was given once the recordings and acoustic analysis had been carried out. The test had two objectives: to characterise people's perception and knowledge of

pose of a particular artefact (appropriateness for a purpose) [48].

56 From Natural to Artificial Intelligence - Algorithms and Applications

in which an interaction between a human and an artefact occurs.

accomplished in a technical, physical, social and organisational environment.

**5.2. Experiments with architecture students**

*5.2.1. The quantitative test*

was performed according to a qualitative approach.

acoustic and sonic features of the outdoor space, and to obtain feedback on the most relevant aspects of street music.

The results should allow for an initial approximation of whether people are aware of the nuances and differences between a street music recording and a concert hall music recording. Above all, it should be possible to test people on the big differences between the acoustics of the different public spaces. Therefore, different recordings of the same music but from different spatial points were compared. A total of six questions, each with a new melody, covered the following topics: speech intelligibility, sense of space, reverberation time, timbre modification, EDT and bass amplification.

The first dataset (**Tables 2** and **3**) shows the description of the analysed elements and the individual responses of the different users.

After an analysis of the survey results, we can highlight some important findings. First, all the questions in **Table 2** are balanced to A or B over 70%, except the fourth question, which is more ambiguous. This shows the high consensus about the acoustic features that were being evaluated. Second, we highlight the presence of users who had professional or higher music qualifications in **Table 3**. These users agreed unanimously, or almost unanimously (except one) in their decisions. The only question on which they disagreed with each other concerns the sense of space.


**Table 3.** Individual options for the quantitative test.

#### *5.2.2. The qualitative test*

In this context, the analysis of some typical street music locations in Ciutat Vella of Barcelona was included in this soundscape evaluation. One of the environments studied here was the Plaça Sant Felip Neri. Various recordings were made in the environment according to different positions of the listeners. For the current study, one recording was selected: *The Fountain* by Marcel Lucien was reproduced in Plaça de Sant Felip Neri in five positions. **Figure 1** shows the emitting point with the enumeration of the different recording points in each square.

Finally, a head mounted display needed to be used to show the virtual reality to the test subjects. The Oculus Rift was selected for this task due to its compact size, high quality display and integrated headphones. This provided a fully immersive environment with a great sense

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The Oculus Rift allows for room scale tracking. This means that the user can move around the real space, and that movement translates to the virtual world. This greatly amplifies the sense of presence and makes the experience a lot more realistic and comfortable. However, it has limitations: the length of the cable and the resolution of the tracking cameras only allow the

To improve this aspect, a teleport system was created. Using the Oculus Rift touch controllers, the user could point to any location in the square, and instantly teleport to that location. This provided the necessary freedom to move around the square, while maintaining all the

user to move around a space 3 m long and 2 m wide, approximately.

**Figure 10.** Two screenshots of what students can see with the glasses.

of presence for the users (**Figure 9**).

**Figure 9.** Three students in the experiment.

benefits of room tracking.

To create the test conditions, Plaça Sant Felip Neri needed to be reproduced as faithfully as possible, in terms of visual and auditory aspects.

First, a 3D model was created using photogrammetric processing of digital images to generate 3D spatial data. This method is relatively fast to implement, does not require specialised hardware like laser scanning and, if performed correctly, produces high quality results that are not as precise as other techniques, but more than enough to transport the user to a faithful 3D recreation of the square.

The next goal was to recreate the soundscape. Two options were developed and presented to the test subjects. The first option was to use the original concert hall recording and present it to the users as it is, without any distortion, reverberation or additional ambient sounds from the square.

The second option was more difficult to create. As stated, five recordings of the song were made from different locations in the square. These recordings captured the subtleties a user would experience listening in the real square. The challenge was to allow the test subjects to move freely around the square and still be able to listen to the song in conditions as close as possible to the real conditions at any point in the square, not only the five recording points.

To extend the experience to any given point, a mixing algorithm was used to perform a logarithmic interpolation between the nearest recordings, to provide an experience that was identical to the original when the user was exactly at the recording point, and faded seamlessly as they moved closer to the next one.

Evaluation between Virtual Acoustic Model and Real Acoustic Scenarios for Urban Representation http://dx.doi.org/10.5772/intechopen.78330 59

**Figure 9.** Three students in the experiment.

**E. Code Male Female**

**U 6**

**U 7**

**U 8**

**U 9**

In this context, the analysis of some typical street music locations in Ciutat Vella of Barcelona was included in this soundscape evaluation. One of the environments studied here was the Plaça Sant Felip Neri. Various recordings were made in the environment according to different positions of the listeners. For the current study, one recording was selected: *The Fountain* by Marcel Lucien was reproduced in Plaça de Sant Felip Neri in five positions. **Figure 1** shows the emitting point with the enumeration of the different recording points in each square.

To create the test conditions, Plaça Sant Felip Neri needed to be reproduced as faithfully as

First, a 3D model was created using photogrammetric processing of digital images to generate 3D spatial data. This method is relatively fast to implement, does not require specialised hardware like laser scanning and, if performed correctly, produces high quality results that are not as precise as other techniques, but more than enough to transport the user to a faithful

The next goal was to recreate the soundscape. Two options were developed and presented to the test subjects. The first option was to use the original concert hall recording and present it to the users as it is, without any distortion, reverberation or additional ambient sounds from the square. The second option was more difficult to create. As stated, five recordings of the song were made from different locations in the square. These recordings captured the subtleties a user would experience listening in the real square. The challenge was to allow the test subjects to move freely around the square and still be able to listen to the song in conditions as close as possible to the real conditions at any point in the square, not only the five recording points. To extend the experience to any given point, a mixing algorithm was used to perform a logarithmic interpolation between the nearest recordings, to provide an experience that was identical to the original when the user was exactly at the recording point, and faded seamlessly as

1. I A A A A A A A A A A A A A A A A A 2. S A A B B A A A A A A A A A A B A A 3. EDT B B B B B B B B A B B A B A B A A 4. Br B A B A A B A B B A B B A A A A A 5. RT A A A A A B A A A A A A A A B A A 6. BR B B B B B B A B B B B B B B A A B

**U 10 (M)**

**U 11** **U 12** **U 13 (M)**

**U 14** **U 15 (M)**

**U 16** **U 17**

**U 5**

**USERS U** 

**1**

*5.2.2. The qualitative test*

3D recreation of the square.

they moved closer to the next one.

**U 2 (M)** **U 3 (M)**

**Table 3.** Individual options for the quantitative test.

possible, in terms of visual and auditory aspects.

**U 4**

58 From Natural to Artificial Intelligence - Algorithms and Applications

Finally, a head mounted display needed to be used to show the virtual reality to the test subjects. The Oculus Rift was selected for this task due to its compact size, high quality display and integrated headphones. This provided a fully immersive environment with a great sense of presence for the users (**Figure 9**).

The Oculus Rift allows for room scale tracking. This means that the user can move around the real space, and that movement translates to the virtual world. This greatly amplifies the sense of presence and makes the experience a lot more realistic and comfortable. However, it has limitations: the length of the cable and the resolution of the tracking cameras only allow the user to move around a space 3 m long and 2 m wide, approximately.

To improve this aspect, a teleport system was created. Using the Oculus Rift touch controllers, the user could point to any location in the square, and instantly teleport to that location. This provided the necessary freedom to move around the square, while maintaining all the benefits of room tracking.

**Figure 10.** Two screenshots of what students can see with the glasses.

The result of this process was an experience that allowed free movement around a realistic 3D recreation of the original square. Users perceived two distinctly different audio environments: one that recreated concert hall conditions, and a second one to experience as closely as possible the square's sound conditions (**Figure 10**).

For the qualitative study, a sample of 18 students (11 men and 8 women) who agreed to participate was selected.

The BLA method works on positive and negative poles to define the strengths and weaknesses of the product. Once the element is obtained, the laddering technique can be applied to define the relevant details of the product. The object of a laddering interview was to uncover how product attributes, usage consequences, and personal values are linked in a person's mind. The characteristics obtained through the laddering application will define which specific factor contributes to the consideration of an element as either a strength or a weakness. The BLA process consisted of three steps, following a similar method to Fonseca, Redondo and Villagrasa [53]:


From the results obtained, the next step was to polarize the elements based on two criteria:

**1.** Positive (Px)/Negative (Nx): the student had to differentiate between elements perceived as strong points of the experience that helped them to consider the music as satisfactory, compared to negative aspects that were not satisfactory or simply needed to be modified to be satisfactory.

The individual values obtained for positive and negative indicators are shown in **Table 5**. Once the features mentioned by the students were identified and given values, the third step defined by the BLA initiated the qualitative stage in which the students described and provided solutions or improvements for each of their contributions in the format of an open interview.

**Table 4.** Positive common (PC), particular (PP), negative common (NC) and negative particular (NP) elements for option

**E. code Description Av. score (Av) Mention index (MI) (%)**

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1PC (A) Clarity of music 7.7 44.4 2PC (A) Guiding thread for music 8.3 16.6 3PC (A) Quality of sound 8.3 16.6 4PC (A) Focused on the music 9 11.1 1PP (A) Peaceful music 9 5.6 1NC (A) Not realistic 3 33.3 2NC (A) No sense of space 4 22.2 3NC (A) No background 4.5 11.1 4NC (A) Movement too fast 4 11.1 1NP (A) No variance of echo 4 5.6 2NP (A) Like a television 4 5.6 3NP (A) Too loud 4 5.6 1PC (B) Realistic 8.4 50 2PC (B) Sense of the place 8.7 33.3 1PP (B) Alive 9 5.6 2PP (B) Softer and modulated 7 5.6 3PP (B) More natural 7 5.6 1NC (B) No clarity of music 3.8 22.2 2NC (B) Relation between background and vision 4.7 16.7 3NC (B) Disturbing background 3.7 16.7 4NC (B) Problems with volume 3.7 16.7 5NC (B) It is not real enough 3.5 11.1 1NP (B) Quality of hardware 5 5.56 2NP (B) Sudden changes in sound 3 5.56

**Table 6** shows the main improvements or changes that the students proposed for both posi-

At this point, we can identify the most relevant items obtained from the BLA, which had high rates of citation, high scores or a combination of both. It is important to separate the types of results obtained. The first group belongs to option A (concert hall recording), and the second

tive and negative elements.

A (concert hall) and option B (public square).

**2.** Common Elements (xC)/Particular (xP): finally, the positive and negative elements that were repeated in the students' answers (common points) and the responses that were only given by one of the students (particular points) were separated according to the coding scheme shown in **Tables 1**–**3**.

The common elements that were mentioned at a higher rate were the most important aspects to use, improve or modify (according to their positive or negative sign). Particular elements, which were mentioned by only one user, could be ruled out or treated in later stages for development (**Table 4**).

Evaluation between Virtual Acoustic Model and Real Acoustic Scenarios for Urban Representation http://dx.doi.org/10.5772/intechopen.78330 61


The result of this process was an experience that allowed free movement around a realistic 3D recreation of the original square. Users perceived two distinctly different audio environments: one that recreated concert hall conditions, and a second one to experience as closely as

For the qualitative study, a sample of 18 students (11 men and 8 women) who agreed to

The BLA method works on positive and negative poles to define the strengths and weaknesses of the product. Once the element is obtained, the laddering technique can be applied to define the relevant details of the product. The object of a laddering interview was to uncover how product attributes, usage consequences, and personal values are linked in a person's mind. The characteristics obtained through the laddering application will define which specific factor contributes to the consideration of an element as either a strength or a weakness. The BLA process consisted of three steps, following a similar method to Fonseca, Redondo and Villagrasa [53]:

**1.** Elicitation of elements. The implementation of the test started with a blank template for the positive (most favorable) and negative (least favorable) elements. The interviewer (in this case the professor) asked the users (the student) to mention a positive and a negative aspect of the two types of music that could be heard (Option A and Option B). Thus, we

**2.** Marking of elements. Once the list of positive and negative elements has been completed, the interviewer asked the user to mark each one from 0 (lowest possible level of satisfac-

**3.** Element definition. Once the elements had been assessed, the qualitative phase started. The interviewer asked for justification of each one of the elements by performing the laddering technique. Questions were asked such as "Why is it a positive element?" "Why did you give it this mark?" The answers had to be specific explanations of the exact character-

istics that made the mentioned element a strength or weakness of the product.

From the results obtained, the next step was to polarize the elements based on two criteria:

**1.** Positive (Px)/Negative (Nx): the student had to differentiate between elements perceived as strong points of the experience that helped them to consider the music as satisfactory, compared to negative aspects that were not satisfactory or simply needed to be modified

**2.** Common Elements (xC)/Particular (xP): finally, the positive and negative elements that were repeated in the students' answers (common points) and the responses that were only given by one of the students (particular points) were separated according to the coding

The common elements that were mentioned at a higher rate were the most important aspects to use, improve or modify (according to their positive or negative sign). Particular elements, which were mentioned by only one user, could be ruled out or treated in later stages for

possible the square's sound conditions (**Figure 10**).

60 From Natural to Artificial Intelligence - Algorithms and Applications

obtained two positive aspects and two negative aspects.

tion) to 10 (maximum level of satisfaction).

participate was selected.

to be satisfactory.

development (**Table 4**).

scheme shown in **Tables 1**–**3**.

**Table 4.** Positive common (PC), particular (PP), negative common (NC) and negative particular (NP) elements for option A (concert hall) and option B (public square).

The individual values obtained for positive and negative indicators are shown in **Table 5**. Once the features mentioned by the students were identified and given values, the third step defined by the BLA initiated the qualitative stage in which the students described and provided solutions or improvements for each of their contributions in the format of an open interview.

**Table 6** shows the main improvements or changes that the students proposed for both positive and negative elements.

At this point, we can identify the most relevant items obtained from the BLA, which had high rates of citation, high scores or a combination of both. It is important to separate the types of results obtained. The first group belongs to option A (concert hall recording), and the second


**Option B** (public square recording). Two main positive aspects were highlighted by students: the high degree of realism of the application both in visual and acoustic terms (MI: 50%, Av: 8.4), and the good relation between sound and place (MI: 33.3%, Av: 8.7). Conversely, some negative comments were pointed out: a lack of clarity in the music (MI: 22.2%, Av: 3.8), a bad relation between background and vision (MI: 16.7%, Av: 4.7), which could be solved with the position of different visual avatars, and the presence of some disturbing background (MI: 16.7%, Av: 3.7), due to the different times of the original recordings. Technically, these would

**Table 6.** Proposed common improvements (CI) and particular improvements (PI) for both positive and negative elements

**E. Code Description Mention index (MI) (%)**

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1CI (A) Improve the relation with the environment 66.7 2CI (A) Improve the background sound 22.2 3CI (A) Change the position of the sounds 11.1 2PI (A) Decrease the volume of the sound 5.7 3PI (A) Improve the relation with the musician 5.7 4PI (A) Improve the quality of the sound 5.7 1CI (B) Improve sound quality 27.8 2CI (B) The changes between position could be softer 22.2 3CI (B) Balance the volume levels between different points 11.1 4CI (B) Improve the relation between vision and sound 11.1 5CI (B) Decrease the background noise 11.1 1PI (B) Improve the clarity of sound 5.7 1PI (B) Improve the relation with the place 5.7

In summary, two clear opinions about the experiment were shown, which confirm the first question of the survey: Which recording do you prefer, A or B? Most people (61.1%) agreed that option B was better than option A (38.9%). The reasons for this answer were clearly explained in the rest of the survey. Although there was a high valuation of the realism of the application both in visual and acoustic terms in option B (MI: 50%, Av: 8.4), it was also certain that clarity of music in option B was not as good as in option A, as we can see if we compare 1PC (A) with 1NC (B). This confirms that the street music recording implies a decrease of quality in the music played. This loss could be a drawback for musicians who want to perform in the middle of the city. However, the survey reveals another feature that must be taken into account: a third of the students (MI: 33.3%) evaluated option B with an almost excellent score (Av: 8.7) for the sense of space quality (2PC [B]). This shows the hidden potential of spatial sound, that is, sound spatialization. Several attempts can be found in the history of music in which composers wrote their music bearing in mind the spatial features of the places in which it was going to be played. However, all these compositions tend to be limited to closed spaces, and the spatial possibilities are limited to the specific space. A wide range of possibilities arise when a closed concert hall is replaced by the openness of squares

be the main aspects to modify in future iterations of the proposed method.

for common and particular items in A recording (concert hall) and B recording (public square).

**Table 5.** Individual scores for PC, PP, NC and PC elements for option A (concert hall) and option B (public square).

group to option B (public square recording). After the elicitation of the most relevant features of each of them, we are going to end by comparing them.

**Option A** (concert hall recording). We can highlight that this kind of recording has good clarity of music (MI: 44.4%, Av: 7.8), it favors the guidance of the thread for music (MI: 16.6%, Av: 8.3), and the quality of the sound is valued (MI: 16.6%, Av: 8.3). In terms of the main negative comments, students clearly identified a lack of realism in this kind of experience (MI: 33.3%, Av: 3), that was related to the lack of sense of space (MI: 22.2%, Av: 4) and they missed the background noise (MI: 11.1, Av: 4.5), aspects that were directly related to the design of the application.


**E. Code Male Female**

**10**

1PC (A) — — — 9 8 — 8 — 7 7 8 — 8 — — — 7 — 2PC (A) 9 — — — — — — 8 — — — — — — — 8 — — 3PC (A) — 8 — — — 7 — — — — — — — 9 — — — 8 4PC (A) — — 8 — — — — — — — — 10 — — — — — — 1PP (A) — — — — — — — — — — — — — — 9 — — — 1NC (A) 2 — — — 3 4 — — — — — — — 3 — 5 — 1 2NC (A) — 2 4 — — — — 5 — — — — — — — — 5 — 3NC (A) — — — — — — 5 — — — — — 4 — — — — — 4NC (A) — — — 5 — — — — 3 — — — — — — — — — 1NP (A) — — — — — — — — — — 4 — — — — — — — 2NP (A) — — — — — — — — — — — 4 — — — — — — 3NP (A) — — — — — — — — — 3 — — — — — — — — 1PC (B) — 9 — — 10 9 7 — 5 9 — 10 — — — 8 — 9 2PC (B) 10 — — 9 — — — 9 — — 4 — — 10 — — 10 — 1PP (B) — — — — — — — — — — — — — — 9 — — — 2PP (B) — — 7 — — — — — — — — — — — — — — — 3PP (B) — — — — — — — — — — — — 7 — — — — — 1NC (B) — — — — — — 4 3 — 4 4 — — — — — — — 2NC (B) — 5 4 5 — — — — — — — — — — — — — — 3NC (B) — — — — — 4 — — — — — 3 — — 4 — — — 4NC (B) 3 — — — — — — — — — — — — — — 5 3 — 5NC (B) — — — — 3 — — — 2 — — — — — — — — — 1NP (B) — — — — — — — — — — — — 5 — — — — — 2NP (B) — — — — — — — — — — — — — — — — — 3

**Table 5.** Individual scores for PC, PP, NC and PC elements for option A (concert hall) and option B (public square).

of each of them, we are going to end by comparing them.

group to option B (public square recording). After the elicitation of the most relevant features

**Option A** (concert hall recording). We can highlight that this kind of recording has good clarity of music (MI: 44.4%, Av: 7.8), it favors the guidance of the thread for music (MI: 16.6%, Av: 8.3), and the quality of the sound is valued (MI: 16.6%, Av: 8.3). In terms of the main negative comments, students clearly identified a lack of realism in this kind of experience (MI: 33.3%, Av: 3), that was related to the lack of sense of space (MI: 22.2%, Av: 4) and they missed the background noise (MI: 11.1, Av: 4.5), aspects that were directly related to the design of the application.

**U 11** **U 12** **U 13** **U 14**

**U 15**

**U 16** **U 17** **U 18**

**USERS U 1 U 2 U 3 U 4 U 5 U 6 U 7 U 8 U 9 U** 

62 From Natural to Artificial Intelligence - Algorithms and Applications

**Table 6.** Proposed common improvements (CI) and particular improvements (PI) for both positive and negative elements for common and particular items in A recording (concert hall) and B recording (public square).

**Option B** (public square recording). Two main positive aspects were highlighted by students: the high degree of realism of the application both in visual and acoustic terms (MI: 50%, Av: 8.4), and the good relation between sound and place (MI: 33.3%, Av: 8.7). Conversely, some negative comments were pointed out: a lack of clarity in the music (MI: 22.2%, Av: 3.8), a bad relation between background and vision (MI: 16.7%, Av: 4.7), which could be solved with the position of different visual avatars, and the presence of some disturbing background (MI: 16.7%, Av: 3.7), due to the different times of the original recordings. Technically, these would be the main aspects to modify in future iterations of the proposed method.

In summary, two clear opinions about the experiment were shown, which confirm the first question of the survey: Which recording do you prefer, A or B? Most people (61.1%) agreed that option B was better than option A (38.9%). The reasons for this answer were clearly explained in the rest of the survey. Although there was a high valuation of the realism of the application both in visual and acoustic terms in option B (MI: 50%, Av: 8.4), it was also certain that clarity of music in option B was not as good as in option A, as we can see if we compare 1PC (A) with 1NC (B). This confirms that the street music recording implies a decrease of quality in the music played. This loss could be a drawback for musicians who want to perform in the middle of the city. However, the survey reveals another feature that must be taken into account: a third of the students (MI: 33.3%) evaluated option B with an almost excellent score (Av: 8.7) for the sense of space quality (2PC [B]). This shows the hidden potential of spatial sound, that is, sound spatialization. Several attempts can be found in the history of music in which composers wrote their music bearing in mind the spatial features of the places in which it was going to be played. However, all these compositions tend to be limited to closed spaces, and the spatial possibilities are limited to the specific space. A wide range of possibilities arise when a closed concert hall is replaced by the openness of squares and public spaces. Coupled volumes, streets, galleries, balconies or even stairs now belong to this new stage for music that can be explored in infinite ways.

**Author details**

\*, Héctor Zapata1

Superior Gandia, Valencia, Spain

University, Barcelona, Spain

\*Address all correspondence to: josep.llorca@upc.edu

, Jesús Alba2

1 AR&M, Barcelona School or Architecture, Universitat Politècnica de Catalunya, Spain 2 Universitat Politècnica de Valencia, Centro de Tecnologías Físicas, Escola Politècnica

3 Grup de Recerca en Technology Enhanced Learning (GRETEL), La Salle-Ramon Llull

[1] Hølleland H, Skrede J, Holmgaard SB. Cultural heritage and ecosystem services: A literature review. Conservation and Management of Archaeological Sites. Jul. 2017;**19**(3):

[2] Barron M. Auditorium Acoustics and Architectural Design. New York: E & FN Spon; 1993 [3] Beranek L. Concert Halls and Opera Houses. New York, NY: Springer New York; 2004

[4] Molerón M, Félix S, Pagneux V, Richoux O. Sound propagation in periodic urban areas.

[5] Kang J. Sound propagation in street canyons: Comparison between diffusely and geo-

[6] Pelat A, Félix S, Pagneux V. On the use of leaky modes in open waveguides for the sound propagation modeling in street canyons. The Journal of the Acoustical Society of

[7] Richoux, Ayrault, Pelat, Félix, Lihoreau. Effect of the open roof on low frequency acoustic propagation in street canyons. Applied Acoustics. Aug. 2010;**71**(8):731-738

[8] Picaut. Numerical modeling of urban sound fields by a diffusion process. Applied

[9] Bullen and Fricke. Sound propagation at a street intersection in an urban environment.

[10] Van Renterghem T, Salomons E, Botteldooren D. Parameter study of sound propagation between city canyons with a coupled FDTD-PE model. Applied Acoustics. Jun.

[11] Can A, Leclercq L, Lelong J, Botteldooren D. Traffic noise spectrum analysis: Dynamic modeling vs. experimental observations. Applied Acoustics. Aug. 2010;**71**(8):764-770

Journal of Applied Physics. Jun. 2012;**111**(11):114906

Journal of Sound and Vibration. Sep. 1977;**54**(1):123-129

America. Dec. 2009;**126**(6):2864-2872

Acoustics. Sep. 2002;**63**(9):965-991

2006;**67**(6):487-510

metrically reflecting boundaries. Feb. 2000. DOI: 10.1121/1.428580

, Ernest Redondo1

Evaluation between Virtual Acoustic Model and Real Acoustic Scenarios for Urban Representation

and David Fonseca3

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65

Josep Llorca1

**References**

210-237
