A Survey on Perceived Indoor Acoustic Quality by Workers from Home during COVID-19 Lockdown in Italy

Round 1

Reviewer 1 Report

 

In this work the authors present results of a survey of the percieved indoor acoustic quality in regard of COVID-19 lockdown. This research is largely based on Ref. [1] (of which all three authors took part as well). However, in my point of view, the similarities between the texts do not reach the level of self-plagiarism.

In terms of the methods used, the paper is not innovative. However, the exceptional time and extraordinary opportunity to collect the questionnaire data is sufficient justification for publishing after addressing the following issues:

- The article presents data poorly. Figures have low resolution and should be better processed. Their use as floats makes the manuscript difficult to read (see e.g. lines 72-76).

- The text makes no distinction as to whether the data comes from city, town or village. With regard e.g. to "animals and sounds of nature" (line 227) it makes quite a difference.

- Although I can imagine the difficulty of such a task, the article does not report on specific details of the construction of each location. The criteria of "apartment block" or "built before 1976" are unfortunately very crude. For example, would it be possible to discuss to what extent building materials may contribute to the statistical uncertainty of the results?

- The article completely lacks a conclusions section - it ends with "discussion".

Author Response

Comments and Suggestions for Authors

In this work the authors present results of a survey of the percieved indoor acoustic quality in regard of COVID-19 lockdown. This research is largely based on Ref. [1] (of which all three authors took part as well). However, in my point of view, the similarities between the texts do not reach the level of self-plagiarism.

In terms of the methods used, the paper is not innovative. However, the exceptional time and extraordinary opportunity to collect the questionnaire data is sufficient justification for publishing after addressing the following issues:

- The article presents data poorly. Figures have low resolution and should be better processed. Their use as floats makes the manuscript difficult to read (see e.g. lines 72-76).

 

Thank you for the suggestion, the quality of the figures was implemented

 

- The text makes no distinction as to whether the data comes from city, town or village. With regard e.g. to "animals and sounds of nature" (line 227) it makes quite a difference.

 

Thank you very much for your suggestion. To better describe where participants were located (because, as suggested, this could have an impact on the noise level), we also introduced the new table 1 which reports the percentage of respondents as a function of the type of city, defined by the number of inhabitants

 

- Although I can imagine the difficulty of such a task, the article does not report on specific details of the construction of each location. The criteria of "apartment block" or "built before 1976" are unfortunately very crude. For example, would it be possible to discuss to what extent building materials may contribute to the statistical uncertainty of the results?

 

Thank you very much for your suggestion. Referring to the Italian building stock, it was indicated by (Nanniperi et al ref. [12]) that the 90% of buildings, realized in Italy in the post-war to nowadays period, has separating walls and outer walls in bricks elements; the 95% of buildings have a prefabricated slab floor with brick blocks. We add in the text the analysis from that study regarding the correlation between the year of house and the expected acoustics quality.

 

- The article completely lacks a conclusions section - it ends with "discussion”.

 

Thank you very much for your suggestion. It was a mistake. The session discussion should have been named discussion and conclusions.

Author Response File: Author Response.docx

Reviewer 2 Report

Paper presents subjective analysis as characterised by annoyance level for indoor and outdoor noise exposure in living spaces. The study is well planned with balanced distribution of sample space as per gender, education, house type and varied noise sources. A robust subjective analysis has been performed to underpin the final conclusion of the impact of indoor noise quality.

Typographical Comments

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Line 210: typo in Table 2 score scale, e.g. 0 1 2 3 5 4

 

Typographical Comments

======================

Line 210: typo in Table 2 score scale, e.g. 0 1 2 3 5 4

 

Technical Comments

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Lines 302-375: 

Although the study has demonstrated the impact of indoor sound quality in living spaces, what is missing and most important, are recommendations to address improvement in indoor sound quality either through policy and/or building best practices.

It would be relevant to highlight open questions for further considerations limited by the scope of the study.

 

Author Response

Paper presents subjective analysis as characterised by annoyance level for indoor and outdoor noise exposure in living spaces. The study is well planned with balanced distribution of sample space as per gender, education, house type and varied noise sources. A robust subjective analysis has been performed to underpin the final conclusion of the impact of indoor noise quality.

Typographical Comments

=================

Line 210: typo in Table 2 score scale, e.g. 0 1 2 3 5 4

thank you for your suggestion, we solved the issue.

Typographical Comments

======================

Line 210: typo in Table 2 score scale, e.g. 0 1 2 3 5 4

thank you for your suggestion, we solved the issue.

 

Technical Comments

==============

Lines 302-375: 

Although the study has demonstrated the impact of indoor sound quality in living spaces, what is missing and most important, are recommendations to address improvement in indoor sound quality either through policy and/or building best practices.

Thank you very much for your suggestion. We added the following sentence at the end of discussion and conclusions session:

Finally, the study has demonstrated the impact of indoor sound quality in living spaces and therefore the necessity to address improvement in indoor sound quality either through policy and/or building best practices. The Italian acoustics community knows very well this important issue, and in January 2023 the new version of standard UNI 11367 on the acoustics classification was published. Moreover, the Italian government recognized this importance recalling UNI 11367 in the new law on the minimum environmental criteria (CAM) for the assignment of the design service for building interventions, for the assignment of works for building interventions and for the joint assignment of design and works for building interventions.

 

It would be relevant to highlight open questions for further considerations limited by the scope of the study.

Thank you very much for your suggestion. We added the following sentence in the conclusions

Taking into account the inevitable limitations due to the small size of the sample investigated which could also lead to some kind of bias, since, as reported in [16], different demographic backgrounds of respondents can influence the answers to a questionnaire, this study confirms the results of other similar studies, both in Italy and in other Countries. 

Author Response File: Author Response.docx

Reviewer 3 Report

 

The paper entitled “A survey on perceived indoor acoustic quality by workers from home during COVID-19 lockdown in Italy” is interesting.  However, the manuscript has a very poor structure and organization (the section 3. Results includes information that should be in the section 2. Materials and Methods, and the manuscript does not even have a Conclusions section). In addition, I have some comments or questions that need to be addressed before this manuscript could be accepted for publication.

INTRODUCTION SECTION.

1.      Introduction section is too short (only three paragraphs and one of them is a single sentence). The authors should provide more background information and highlight why this study is relevant. The discussion section includes similar previous studies conducted in Italy and other countries, the authors should also include them in the Introduction section and provide information about them.

MATERIALS AND METHOD SECTION.

2.      Some paragraphs of the manuscript are duplicated. E.g.: (Line 72-76): “The sample of respondents… …diploma (Figure 2)” and (Line 79-56): “The sample of respondents… …diploma (Figure 2)”.

3.      The authors should discuss whether the sample of 330 responses is sufficient for this study.

4.      (Line 75) “…and generally with a high level of education. 74% of respondents reported having at least a Master’s degree and 25% a high school diploma”. Why were no responses obtained from participants with less level of education? Previous research showed that demographic factors such as educational level influenced housing affordability (Bujang, 2010). Authors should discuss and include in the manuscript if the data obtained from the survey were biased by this fact and the limitations of the study.

Bujang, A. A., Zarin, H. A., & Jumadi, N. (2010). The relationship between demographic factors and housing affordability. Malaysian Journal of Real Estate, 5(1), 49-58

5.      (Line 84): “When the respondents submitted the questionnaire, 75% of them had been WFH for more than 1 month and 22% for more than 2 weeks”. And what about the remaining 3%? Those participants did not work from home? 

6.      (Line 95): “As regards the indoor neighborhood noise, only the apartment blocks (73%, N = 241) have been taken into consideration since, as they are adjacent to each other (above, below and to the side), they are more likely to be subject to noise transmission”. Terraced house are adjacent to each other and the likelihood of being subject to noise transmission (to the side) is identical to that of apartment blocks. Why didn't the authors include it in the analysis? The authors should provide a detailed explanation, carry out the analysis of this type of housing and include it in the manuscript.

7.      (Line 100):  “The average age of the Italian apartment block buildings is very high (Figure 4)” and “Our survey shows that 183 respondents indicated that the buildings were built before 2000 and only 51 after 2000 (22% 110 of the total).” However, the fact that the building was built before 2000 does not necessarily imply that no renovations were made afterwards to improve the acoustic insulation and performance. (Line 114): “Therefore, in order to identify a possible improvement in acoustic performance, with reference to Figure 4, it can be assumed that 52% of the respondents (14%+8%+13%+17%) may have benefited from better outdoor sound insulation but only 22% (8% + 14%) have benefited from both better indoor and outdoor sound insulation.”  The authors do not have sufficient evidence to assume this hypothesis to be true.

8.      Authors should include in the Materials and Methods section the questions included in the questionnaire on Acoustic Quality.

RESULTS SECTION

9.      Figures should be insert in the main text after the paragraph of its first citation. The authors should review this issue. E.g. the first citation of Figure 6 is in line 128 (page 4), while Figure 6 is inserted in page 6.

10.    (Line 135): “The data analysed are related to the answers to the following question: With reference to the current (i.e. lockdown) period, how annoyed or irritated are you by the noise coming from outdoor, from the neighborhood and from the interior of your home?” Authors should indicate the scale provided to the participants to indicate the response to this question.

11.   (Line 138): “Indoor and outdoor noise sources indicated for this question as summarized in Table 1”. This sentence refers to the question: “how annoyed or irritated are you by the noise coming from outdoor, from the neighborhood and from the interior of your home?” As far as I can understand, the objective of this question is to know HOW annoyed or irritated..., and not the sources of the noise that generates that annoyance. The authors should provide an explanation for this fact.

12.   Was the questionnaire used in this field study previously validated? The questionnaire validation was not clearly explained in the manuscript. The authors should explain this issue in detail in the manuscript given the impact it has on the collected data.

13.   The section 3.1. Noise annoyance during lockdown does not provided results. From line 135 to 151, the authors provided information about the questionnaire used in the field survey, but not results. That information should be included in the Materials and Methods section, while section 3.1 should only present the results obtained in relation to noise annoyance.

14.   Figure 6 should be modified. The colours used to indicate "very" and "extremely" are barely distinguishable.

15.   (Line 161) : “The data on road traffic noise differ from those on other types of traffic (36% of annoyed)”; How was the percentage of respondents annoyed with traffic noise (i.e., 36%) calculated? Was it calcualted over the whole sample or over the respondents who do not open the windows?

16.   (Line 167): “On the contrary, the most perceived and disturbing outdoor noises are those of anthropogenic origin, (shouting, children playing, etc.), which 52% …”. Same issue as in the previous comment. How was this percentage calculated? Was it calculated over the whole sample? Does it consider all types of housing? Authors should explain these aspects since it may cause confusion for future readers.

17.   (Line 182): “annoying (38 ÷ 39%)”. Author should change the symbol.

18.   Section 3.2. Changes between pre-lockdown and lockdown period, from line 195 to 216 (including Table 3), and Section 3.3, from line 264 to line 270, do not provided the results obtained in this study. This information should be moved to Material and Method section.

19.   The first citation of Table 4 is in line 252, while Table 4 is inserted in line 248.

20.   Do the authors think that the sample of 330 participants is sufficient to infer the results to a larger population?

21. (Line 161): "The data on road traffic noise differ from those on other types of traffic (36% of annoyed); this can be explained by the sirens of the many ambulances driving by during the lockdown period, ...". Is this assumption always true? Even in towns or villages? Is the sample of respondents evenly distributed across towns and cities? Or could this fact also condition the survey results?

DISCUSSION SECTION.

22.   (Line 360): “Taking into account the inevitable limitations due to the small size of the sample investigated and the online approach, this study confirms the results of other similar studies, both in Italy and in other Countries”. Authors should include references to these previous studies developed in Italy and other countries. Furthermore, and as the Authors state, given the small population size of this study, it only confirms the results of similar studies. So, what is the novelty and the new findings of this study?

23.   Since the manuscript does not have a conclusion section, authors should add one. Conclusion section should describe the most important conclusions, the main new findings obtained in this study, the relevance of their novelty and the take-home messages.

 

 

Author Response

The paper entitled “A survey on perceived indoor acoustic quality by workers from home during COVID-19 lockdown in Italy” is interesting.  However, the manuscript has a very poor structure and organization (the section 3. Results includes information that should be in the section 2. Materials and Methods, and the manuscript does not even have a Conclusions section). In addition, I have some comments or questions that need to be addressed before this manuscript could be accepted for publication.

INTRODUCTION SECTION.

1. Introduction section is too short (only three paragraphs and one of them is a single sentence). The authors should provide more background information and highlight why this study is relevant. The discussion section includes similar previous studies conducted in Italy and other countries, the authors should also include them in the Introduction section and provide information about them.

Thank you very much for your suggestion. We have added in the introduction section more background information, describing previously published work and explaining why our study is relevant.

MATERIALS AND METHOD SECTION.

2. Some paragraphs of the manuscript are duplicated. E.g.: (Line 72-76): “The sample of respondents… …diploma (Figure 2)” and (Line 79-56): “The sample of respondents… …diploma (Figure 2)”.

Thank you very much for your suggestion. We have deleted the second paragraph, after figure 2

3. The authors should discuss whether the sample of 330 responses is sufficient for this study.

Thank you very much for your suggestion. The sample refers only to workers in WFH and it is a sample based on voluntary collection of information. We added this limit of the study in the discussion and conclusions section.

 

4. (Line 75) “…and generally with a high level of education. 74% of respondents reported having at least a Master’s degree and 25% a high school diploma”. Why were no responses obtained from participants with less level of education? Previous research showed that demographic factors such as educational level influenced housing affordability (Bujang, 2010). Authors should discuss and include in the manuscript if the data obtained from the survey were biased by this fact and the limitations of the study..

Bujang, A. A., Zarin, H. A., & Jumadi, N. (2010). The relationship between demographic factors and housing affordability. Malaysian Journal of Real Estate, 5(1), 49-58

Thank you very much for your suggestion. We have referred the proposed paper and included this kind of limitation of our study in the discussion and conclusions section. We would like to emphasize that "this study confirms the results of other similar studies, both in Italy and in other Countries".

5. (Line 84): “When the respondents submitted the questionnaire, 75% of them had been WFH for more than 1 month and 22% for more than 2 weeks”. And what about the remaining 3%? Those participants did not work from home? 

Thank you very much for your suggestion. We added: the remaining 3% WFH between one and two weeks.

6. (Line 95): “As regards the indoor neighborhood noise, only the apartment blocks (73%, N = 241) have been taken into consideration since, as they are adjacent to each other (above, below and to the side), they are more likely to be subject to noise transmission”. Terraced house are adjacent to each other and the likelihood of being subject to noise transmission (to the side) is identical to that of apartment blocks. Why didn't the authors include it in the analysis? The authors should provide a detailed explanation, carry out the analysis of this type of housing and include it in the manuscript.

Thank you very much for your suggestion. Based on the paper from Nannipieri et al. (ref. [12]) we considered the Italian building stock and the issues about its acoustics quality. A detailed explanation on this was added in paragraph 2.3. Moreover, we added an explanation of why we didn’t take into account terraced houses in the same paragraph.

7. (Line 100):  “The average age of the Italian apartment block buildings is very high (Figure 4)” and “Our survey shows that 183 respondents indicated that the buildings were built before 2000 and only 51 after 2000 (22% 110 of the total).” However, the fact that the building was built before 2000 does not necessarily imply that no renovations were made afterwards to improve the acoustic insulation and performance. (Line 114): “Therefore, in order to identify a possible improvement in acoustic performance, with reference to Figure 4, it can be assumed that 52% of the respondents (14%+8%+13%+17%) may have benefited from better outdoor sound insulation but only 22% (8% + 14%) have benefited from both better indoor and outdoor sound insulation.”  The authors do not have sufficient evidence to assume this hypothesis to be true.

Thank you for your suggestion. At the end of paragraph 2.3 we added a discussion about the correctness of our assumption.

8. Authors should include in the Materials and Methods section the questions included in the questionnaire on Acoustic Quality.

Thank you very much for your suggestion. We added in material and method the reference to annex A of this manuscript in which all the questions and answers about acoustics are indicated.

RESULTS SECTION

9. Figures should be insert in the main text after the paragraph of its first citation. The authors should review this issue. E.g. the first citation of Figure 6 is in line 128 (page 4), while Figure 6 is inserted in page 6.

Thank you very much for your suggestion. We solved the issue.

10. (Line 135): “The data analysed are related to the answers to the following question: With reference to the current (i.e. lockdown) period, how annoyed or irritated are you by the noise coming from outdoor, from the neighborhood and from the interior of your home?” Authors should indicate the scale provided to the participants to indicate the response to this question.

Thank you very much for your suggestion. We added in Annex A all the all the questions and possible answers about acoustics, to show also the scale provided to participants.

11. (Line 138): “Indoor and outdoor noise sources indicated for this question as summarized in Table 1”. This sentence refers to the question: “how annoyed or irritated are you by the noise coming from outdoor, from the neighborhood and from the interior of your home?”As far as I can understand, the objective of this question is to know HOW annoyed or irritated..., and not the sources of the noise that generates that annoyance. The authors should provide an explanation for this fact.

Thank you very much for your suggestion. In materials and methods, we added the reference to standard ISO/TS 15666:2003 “Acoustics — Assessment of noise annoyance by means of social and socio-acoustic surveys”, which provides specifications for socio-acoustic surveys and social surveys, which include questions on noise effects.

12. Was the questionnaire used in this field study previously validated? The questionnaire validation was not clearly explained in the manuscript. The authors should explain this issue in detail in the manuscript given the impact it has on the collected data.

Thank you very much for your suggestion. We referred to ISO/TS 15666:2003. We have inserted this reference in paragraph materials and methods.

13. The section 3.1. Noise annoyance during lockdowndoes not provided results. From line 135 to 151, the authors provided information about the questionnaire used in the field survey, but not results. That information should be included in the Materials and Methods section, while section 3.1 should only present the results obtained in relation to noise annoyance.

We agree with your suggestion to delete the information about the questionnaire from section 3.1. To give the reader more details, we have included in the new Appendix A all the details about the questionnaire and the possible answers.

14. Figure 6 should be modified. The colours used to indicate "very" and "extremely" are barely distinguishable.

Thank you very much for your suggestion. This issue was solved.

15. (Line 161) : “The data on road traffic noise differ from those on other types of traffic (36% of annoyed)”; How was the percentage of respondents annoyed with traffic noise (i.e., 36%) calculated? Was it calcualted over the whole sample or over the respondents who do not open the windows?

Thank you very much for your suggestion. For the sake of clarity, we added in line 161 the following sentence:

The following considerations regard the total of respondents (Fig. 6 a).

16. (Line 167): “On the contrary, the most perceived and disturbing outdoor noises are those of anthropogenic origin, (shouting, children playing, etc.), which 52% …”. Same issue as in the previous comment. How was this percentage calculated? Was it calculated over the whole sample? Does it consider all types of housing? Authors should explain these aspects since it may cause confusion for future readers.

Thank you very much for your suggestion. For the sake of clarity, we added in line 161 the following sentence:

The following considerations regard the total of respondents (Fig. 6 a).

 

17. (Line 182): “annoying (38 ÷ 39%)”. Author should change the symbol.

The symbol is traditionally used to indicate “from …… to ….”. For the sake of clarity, to avoid possible misunderstanding in indicating the values of the ranges, we changed the symbol “÷” with the one “-“.

18. Section 3.2. Changes between pre-lockdown and lockdown period, from line 195 to 216 (including Table 3), and Section 3.3, from line 264 to line 270, do not provided the results obtained in this study. This information should be moved to Material and Method section.

Regarding lines 195-216 and 264-270: the text and Tables 2 and 3 have been deleted because the information are listed in the new Appendix A, which contains all the questions and possible answers. A new subsection 2.1 has been added to explain the standard used to design and develop the questionnaire.

19. The first citation of Table 4 is in line 252, while Table 4 is inserted in line 248.

Table 4 (now Table 2) is now cited before the table in the text.

20. Do the authors think that the sample of 330 participants is sufficient to infer the results to a larger population?

Thank you very much for your suggestion. We added the following sentence in the discussion and conclusions section

Taking into account the inevitable limitations due to the small size of the sample investigated which could also lead to some kind of bias, since, as reported in [15], different demographic backgrounds of respondents can influence the answers to a questionnaire,  this study confirms the results of other similar studies, both in Italy and in other Countries.

21. (Line 161): "The data on road traffic noise differ from those on other types of traffic (36% of annoyed); this can be explained by the sirens of the many ambulances driving by during the lockdown period, ...". Is this assumption always true? Even in towns or villages? Is the sample of respondents evenly distributed across towns and cities? Or could this fact also condition the survey results?

The fact that northern regions were mostly affected by the pandemic (also confirmed by other authors such as Bartalucci) can help explain the case of road traffic noise during lockdown. On the other hand, a sample unbalanced towards the northern regions does not seem to have been considered an important limit in other studies already published (Salamone, Bartalucci).

For the sake of clarity we added table 1 in paragraph 2.2 showing the sample distribution over the type of city.

DISCUSSION SECTION.

22. (Line 360): “Taking into account the inevitable limitations due to the small size of the sample investigated and the online approach, this study confirms the results of other similar studies, both in Italy and in other Countries”. Authors should include references to these previous studies developed in Italy and other countries. Furthermore, and as the Authors state, given the small population size of this study, it only confirms the results of similar studies. So, what is the novelty and the new findings of this study?

Thank you very much for your suggestion. We have added in the introduction section more background information, describing previously published work and explaining why our study is relevant.

 

23. Since the manuscript does not have a conclusion section, authors should add one. Conclusion section should describe the most important conclusions, the main new findings obtained in this study, the relevance of their novelty and the take-home messages.

Thank you very much for your suggestion. It was a mistake. The session discussion should have been named discussion and conclusions.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The authors answered my questions and updated the text, which is now ready for publication.

Reviewer 3 Report

The authors have successfully addressed my previous comments.