DNP Scientifically Demonstrates Ease of Conversation via Low Reflective and Low Sound Insulation Partition

Tokyo, July 28, Dai Nippon Printing Co., Ltd. (DNP) has commenced research related to the impact on human face-to-face communication of the low reflective and low insulation film partition. This venture will be conducted under the academic guidance of Professor Tetsuya Sakuma of the University of Tokyo, who specializes in environmental acoustics. 

In this latest development, we confirmed that it is easier to transmit the voice, and also that it is easier to conduct conversation compared with conventional acrylic board partitions. The new product that helps to prevent droplet infection, makes it easier to both see each other's facial expressions by suppressing light reflection, and to hear the other person’s voice by lowering the sound insulation.

Image of dialogue using the low reflective and low insulation film partition, which has been introduced in-house as a preventative measure against the spread of the Covid-19 virus

Overview of Acoustic Evaluation Performance and Communication Evaluation

Evaluation method 

The low reflective and low insulation film partition, with a thickness of 0.25 mm, and two types of partition, a polyethylene terephthalate (PET) film with a thickness of 0.025 mm, and a 2 mm acrylic board, were prepared for comparison. Each partition was evaluated for ease of transmitting the voice, or an acoustic performance evaluation1, and the ease with which to conduct a conversation, or the communication evaluation2.

1: Scheduled to be announced at the 2022 Architectural Institute of Japan Convention 
2: Scheduled to be presented at the 2022 Acoustical Society of Japan Autumn Research Presentation

In the acoustic performance evaluation, the level of sound pressure through the partition was measured. In the communication evaluation, a group of two people engaged in a 3-minute conversation through the partition, then replied to a questionnaire regarding their impressions of conversation and voice quality along with visible appearance.   

Image of acoustic evaluation performance

Image of communication evaluation

Evaluation results

In the acoustic performance evaluation, it was found that the low reflective and low insulation film partition has lower sound insulation performance than the acrylic board partition, and that sound was easily transmitted.

The thinner the material, the easier it was for the sound to be transmitted, but the thinner the material, the easier it was to break up, and there were other issues, such as the film shaking due to air conditioning. To overcome these issues, low reflective and low insulation film partition uses a film that is about one-tenth as thin as that of an acrylic board. 

In the communication evaluation, it was found that the presence or absence of an anti-reflective performance affects the evaluation. The low reflective and low insulation film partition maintains a lower reflectance than PET film registered the lowest sound insulation performance in the acoustic performance evaluation. It was seen to exhibit a tendency towards a higher evaluation as an item related to ease of conversation, ease of hearing, and loudness of the voice. The results were consistent with such impressions as “being able to engage in a natural conversation,” obtained from users, and it was found that engaging in conversation was easy.

Looking Ahead

DNP will make a further study of the visual improvement effect of lower light reflection on overall communication, including ease of hearing, in addition to such mass related laws, as the relationship between partition thickness and sound insulation. Under the guidance of Professor Sakuma, we will conduct an impression evaluation experiment that mimics actual conversation, and reveal the complex relations regarding the effects of sound insulation and light reflection on communication comfort. We will develop this product as a tool for stress-free and comfortable communication while maintaining our infection control measures.

[Further information]

*For the January 20, 2022 news release regarding the development of Low Reflective and Low Sound Insulation Film Partition, please visit,
*For further information regarding ultra-low reflection face shield, please visit

*No claims are made regarding the capability of the low reflective and low insulation film partition to fully prevent bacterial and viral infections.
*Listed product specification and service contents are current as of the date of publication. They may be changed at any time without notice.

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