ローノイズマイクロホン＆音響パワーレベル計測システム

Microphones are sensors that convert sound into electrical signals and measure sound levels and pitch. Microphones have a type of noise called 'self-noise,' which is noise generated by the microphone itself. Sounds that are smaller than this self-noise cannot be accurately measured; however, the newly released low-noise microphone has reduced the self-noise level to world-class standards, enabling the measurement of very faint sounds in the 10dB range, which is difficult for conventional measurement microphones. In recent times, especially after the COVID-19 pandemic, the demand for noise control has become stricter, and this microphone is expanding its applications in industries such as air conditioning and automotive, where quiet operation is particularly sought after.

According to our research, this is the product with the lowest self-noise level among microphones with a diameter of 1/2 inch. Additionally, it is the first domestic low-noise microphone to adopt a 'back electret type' structure, allowing it to be directly connected to analysis equipment, making it more user-friendly and reducing implementation costs.

Yes, that's right. I am one of the developers, and since this project involved many tasks, our microphone development team worked together as a whole. To reduce the self-noise level to below 10dB, we had to go beyond our company's previous technical limits, so we revisited the fundamentals of physical phenomena and progressed by rebuilding from scratch. Moreover, the introduction of simulations as a new method, proposed by the team leader, was also a significant point.

In general, simulation tools are often utilized in the design of electronic circuits, but this time we incorporated a method to model the physical phenomena of microphones, allowing us to evaluate both the physical phenomena and the electronic circuit together in the simulator. By reducing the process of creating and evaluating physical objects and being able to adjust parameters in the simulator, I believe this was a breakthrough in this development that led to good results. Additionally, low-noise microphones are very delicate as they can pick up even the faintest sounds, so it was quite challenging to establish a system for stable quality mass production. I am very pleased that we were able to reach the actual release by having detailed discussions and coordinating closely with all parties involved.

The development team has achieved performance beyond what I initially planned. This development was the first product for which I was fully responsible for planning, so there were many challenges as I learned while leading. However, the development team produced excellent results, and I feel that I have grown through this experience, making it worthwhile to take on this development challenge.

In recent years, there has been a trend towards noise reduction in various industries, leading to a high demand for "more accurate measurement of quieter sounds." Customers, especially those with such needs, have been very pleased. Although the product is more expensive than standard microphones, it is also priced lower than comparable products from other companies, which is appreciated.

The sound power level is an indicator of noise that captures sound emitted from equipment over a radiation surface rather than a single point. The sound level of the equipment can vary depending on the measurement location, but this sound power level is standardized by international regulations, making it a globally accepted measure of noise used in various industries such as office equipment, HVAC systems, home appliances, and automotive parts. This time, we have released a new system using our Sound and Vibration Analysis System DS-5000 and O-Solution, which was launched a few years ago.

By enabling the saving of measurement results as reports and adding features that assist in cause analysis, it has become easy to conduct not only measurements but also detailed analyses and identify sound source locations afterward. Additionally, in recent years, there has been an increase in products that emit high sounds, such as motors, prompting an expansion of the measurement range to frequencies higher than international standards.

This has also received positive feedback. It is an honor that the Japan Quality Assurance Organization (JQA), which is essential for quality assurance in Japan, has adopted the O-Solution DS-5000 Sound Power Level Measurement System using a low-noise microphone. By using the low-noise microphone, it is possible to evaluate sounds that are smaller than those measured with a standard microphone, contributing to the improvement of quality assurance in Japan, and we are very pleased to have received positive responses from the person in charge.

In the development of this product, we not only interpreted various international standards and incorporated them into the software, but also visited customers to hear their usage and requests, aiming for a simpler and more user-friendly product. It was challenging to achieve specifications that comply with the standards while also considering usability, but I believe that effort led to a good product. Additionally, the development team, including myself, deepened our understanding of the standards and improved our skills through this development process, which I think was a positive outcome.

The development of this low-noise microphone was initiated by the increasing demand for quietness, but I believe that the products customers need change with the times. Moving forward, I want to quickly capture the changing needs of our customers and focus on product development that addresses those needs.

Personally, I was able to gain a lot in terms of skills related to electronic circuits through this development. I hope to fully utilize the skills I have acquired in the next product development.

Since the sound power level is defined by standards, it is important to respond properly when those standards are revised. Additionally, rather than just measuring and finishing, we want to continue upgrading by adding features that help solve issues for customers who want to 'reduce sound'.