PONE-D-21-14020

Groove arrays in the ears of mammals and owls enhance acoustic information.

PLOS ONE

Dear Dr. Keeley,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

In particular, it is important you address the issue of multiple repetitions of the measurements. This would be needed to ensure the results are statistically sound. Further discussing the relevance of your measurements to real signals perceived by bats and owls would also be useful, given the title of your paper.

Please submit your revised manuscript by Sep 06 2021 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

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We look forward to receiving your revised manuscript.

Kind regards,

Vivek Nityananda

Academic Editor

PLOS ONE

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Partly

Reviewer #2: Yes

Reviewer #3: Partly

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2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: No

Reviewer #2: Yes

Reviewer #3: N/A

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3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: No

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4. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

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5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: This is an interesting experimental investigation into the role of grooves patterns that can be found in bat ears. However, if I understand the description of the methods and the results correctly, the comparisons between grooved and smoothed shapes were done using only single acoustic measurement for each shape. In practice, acoustic measurements and spectrum estimates based on them are subject to a very high level of variability. It is hence absolutely essential that the authors add multiple repetitions to their measurements and investigate which of the observed differences are statistically significant. Without such an analysis, it is impossible to draw any conclusions from the obtained results.

In addition, I believe that it is essential for the authors to remove all mentions of "acoustic information" from their hypotheses since there is nothing in their work/analysis that could be seen as measuring information.

Finally, the authors should comment on how the studied frequency range compares to the frequency bands known to be utilized by bats and owls.

Here some minor issues I have come across:

l. 47: There seems to be no benefit to using the term "polyphonic"

here, which afaik means independent melodies, not just multiple

frequencies in music .

l. 82: Would say "phase relationships" to avoid confusion with medical

use of phasic (i.e., short-term).

l. 83: Use "broadband" instead of "polyphonic".

l. 123: It is not informative to say that the pinna models were based

on "discussions with acoustic specialists", instead the specialists

should be thanked in the acknowledgments.

l. 134: The "z" in "kHz" is not capitalized.

l. 150: More information about the prey noise should be given, e.g.,

bandwidth, spectral shape (flat, lowpass, bandpass characteristics).

l. 196 - 198: It appears that no repetitions of the expriments

l. 340: Capitalize "B" in "dB".

l. 359: Remove comma after "Kuc".

Reviewer #2: This paper presents that the groove arrays on the ear model increase the signal intensity compared to the smooth model. It provides fundamental study for many further open questions. There are a few concerns that could be addressed to improve the quality of the paper.

1. This paper mainly investigates the effect of groove array on the general ear model instead of the animal’s ear. I’d recommend that the Short Title is more appropriate than the Full Title.

2. A setup figure (or a sketch of the emitter, ball, sandpaper discs, etc) shows how those three sound sources are generated will help the reader to understand.

3. Including example spectrograms of array model and smooth model in Fig 6 could help the reader to understand how you get the dB difference plots.

4. Please make sure all figures have x-axis and y-axis labels/units and suitable font sizes. In fig 8, the time duration (1000 ms) in the x-axis should be consistent for all subplots.

5. In line 50 “Huygens-Fresnell principle” should be “Huygens-Fresnel principle”.

In line 250 “...intense. in signal strength...”.

In line 338 “db” should be “dB”.

6. In line 131, is there any specific reason to choose the ear model dimensions to be 28 mm X 44 mm?

7. Is the statement in lines 308-309 based on the results from fig 6? If so, it is different from the statement of lines

236-237.

8. The statement in line 314: “The influence of the arrays appears to diminish as the distance increases with one sound

source but not another.” Replace the “one sound source, another” with the specific name of the sound source to

avoid ambiguity.

9. In the “Discussion” section, the author mentioned “traditional diffraction grating studies” many times and compared

their results with it. References are needed to the “traditional diffraction grating studies”.

10. Did the prey sound test involve 10 models and 5 distances as well? If so, any further statistical analysis could be

put into the supplementary material. Currently, only one fig (fig 7) shows one condition.

11. In lines 337-338: “This study demonstrates that the presence of arrays appears to be able to enhance the signal

strength across the spectral envelope, but the effective distance may vary according to the sound source.”

The “sound source” here indicates 3 different types of sound sources that are continually mentioned in the paper or

different frequency sounds from the "40kHz sound source"? It should be stated more clearly.

Reviewer #3: There are two major issues with this paper.

1. The ridges do much better than the pinna without ridges, particularly the increase in gain. Could there be a problem with that pinna that evolution has solved using thin flexible skin?

2. More important than 1: The paper gives quantitative and qualitative results that indicate the effect of the ridges, but little analysis or explanation on how they would benefit a bat. The experiments and ridge designs were too exhaustive in scope. This reviewer would have liked to see one or two signals with the best ridge design, in the author's opinion, to demonstrate the benefit of the ridges, beyond that the ridges modify the detected signals.

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Reviewer #1: No

Reviewer #2: Yes: Xiaoyan Yin

Reviewer #3: No

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PONE-D-21-14020R1Acoustic wave response to groove arrays in model ears.PLOS ONE

Dear Dr. Keeley,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

==============================In particular, it would be important to clarify the point raised by the reviewer about what exactly the variability in the measurements entails.==============================

Please submit your revised manuscript by Nov 12 2021 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:

• A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.
• A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.
• An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols.

We look forward to receiving your revised manuscript.

Kind regards,

Vivek Nityananda

Academic Editor

PLOS ONE

Journal Requirements:

Please review your reference list to ensure that it is complete and correct. If you have cited papers that have been retracted, please include the rationale for doing so in the manuscript text, or remove these references and replace them with relevant current references. Any changes to the reference list should be mentioned in the rebuttal letter that accompanies your revised manuscript. If you need to cite a retracted article, indicate the article’s retracted status in the References list and also include a citation and full reference for the retraction notice.

Additional Editor Comments (if provided):

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: (No Response)

Reviewer #3: All comments have been addressed

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2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Partly

Reviewer #3: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: I Don't Know

Reviewer #3: N/A

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #3: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: No

Reviewer #3: Yes

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: The revision address all my concerns with the exception of the variability in the measurements. The manuscript should clarify whether 5 measurements were made for each of the 5 different distances, or just one measurement was made per distance. In the former case, error bars (e.g., max and min differences found) should be included in Fig. 6 to show the variability of the measurements. If only 1 measurement per distance has been made been made, additional measurements should be done to assess the variability in these experimental results.

Reviewer #3: (No Response)

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7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No

Reviewer #3: No

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.

Acoustic wave response to groove arrays in model ears.

PONE-D-21-14020R2

Dear Dr. Keeley,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

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Kind regards,

Vivek Nityananda

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Reviewers' comments: