■ What is the Self-Dummy Head Service

This is a unique service that maximizes the entirely new music experience '8K SOUND' of the flagship wireless earphones ZE8000 to suit the individual. By forming a 'Self-Dummy Head' from intricate data obtained from the upper body of each person using a special measurement method, and further investing in a uniquely developed 'virtual sound environment', the ZE8000 delivers sound alignment tailored to each individual from the obtained data.

・Based on shape data measured at 864 points across the entire upper body, not just the ears, the acoustic physical quantities are meticulously derived using COMSOL*1's physical simulation.
・final independently developed original software to control the acoustic physical quantities of self-dummy heads in virtual sound spaces.

Additionally, by processing ear pieces specifically for the ZE8000 MK2 to enhance sealing and retention, self-dummy head-specific silicon ear pieces are adopted. From a complex perspective, we realize an "improvement in sound quality."

 ■ About Sound Quality

Sound quality is the source of all impressions you feel when hearing a sound, excluding the pitch, volume, and direction of the sound.
For example, when you perceive something dangerous approaching just by the sound, you know the location of that thing from the sound and infer what it is from the sound. The former is sound direction perception, and the latter is sound quality recognition. Since we can recognize sound quality, we can understand the differences between various instruments and voices solely through sound.
In other words, sound quality is the most important element for enjoying music composed of different instruments and voices.

The purpose of the self-dummy head service is to enhance the sound quality reproduction capability of earphone content, allowing for more enjoyment of music.

 ■ Points of the Self-Dummy Head Service

1: Implement individual sound quality optimization different from the previous service.

2: The ZE8000 dedicated app "final CONNECT" is updated to the self-dummy head service customer version.

3: Based on the ZE8000 MK2-specific ear pieces, processed silicon ear pieces dedicated to this service are used.

4: Laser engraving of self-dummy head verification marks on the body

■ From Application to Delivery

Third Application Round

【Application Method】
Please apply by selecting your preferred date and time for DAY1 and DAY2 from the following application form.

【Application Period】
From February 21, 2025 (Friday) to February 25, 2025 (Tuesday) 23:59

【Number of Recruits】
6 people

【Selection Announcement】
We will contact only those selected via the registered email address by February 27, 2025 (Thursday).

DAY1 (Required Time: 2 hours)

［STEP1］
Receive the ZE8000 you brought.

［STEP2］
Explanation about the self-dummy head by staff.

［STEP3］
Upper body 3D scan.

［STEP4］
3D scan of the ear and outer ear canal entrance.

［STEP5］
Measurement of the physical properties of the outer ear canal.

［STEP6］
Loan of substitute products.

DAY 2 (Required Time: Approx. 3 hours)

［STEP1］
Final alignment by acoustic test.

［STEP2］
Explanation of the self-dummy head service-specific app functions.

［STEP3］
Return of substitute products.

［STEP4］
Confirmation of delivery date and destination.

※ Delivery
The self-dummy head-applied ZE8000 will be sent to the specified address at the specified date and time.

■ Concept of the Self-Dummy Head Service

At final, we utilize the unique concept of a virtual sound environment to research and develop subjects to be listened to with transducers (2ch stereo sound sources) created content. This concept aims to surpass the limitations of traditional transducer product development, which has primarily relied on physical measurement and subjective evaluation of sound.

In this virtual sound environment, we have advanced research and development for the services presented this time by incorporating a model called "self-dummy head," created based on precise body shape measurements. By incorporating the self-dummy head into a virtual sound environment, it is possible to verify two important auditory phenomena: "sound direction perception" and "sound quality recognition." When we listen to music with earphones, we enjoy not only the position of the sounds of each instrument and vocal but also the sounds themselves of each instrument and vocal.

The diagram above is a simplified explanation of a figure included in a paper presented by Günther Theile, a German acoustics researcher, in the AES Journal in 1986. It is a model showing how sound reaching the eardrum is processed both physically and psychoacoustically. The important point here is that spatial hearing and gestalt recognition are processed in separate stages. Gestalt recognition is a psychological concept of recognizing shapes instantly, allowing one to recognize and understand the timbre of each instrument or vocal sound in music listening as previously explained.

Basing on the model presented by Günther Theile, it becomes possible to handle sound direction perception and timbre recognition independently. This time, the service we are presenting is aimed not at sound direction perception, but at improving the quality of timbre recognition.
The acoustical physical characteristics obtained from one's own dummy head placed in the virtual sound environment introduced earlier are being utilized to enhance timbre recognition based on the concept of the model shown by Günther Theile. As a result, the timbre of instruments and vocals is improved, and the balance between instruments and vocals can also be enhanced. The obtained information is digitized through simulation technology, and this data is reflected in your ZE8000 and delivered to you.

■ Why measure the upper body

In a free field without any reflections (e.g., an anechoic chamber), when a perfect omnidirectional sound source (a sound source without any specific directional frequency characteristics) is listened to by multiple people at equal distances from the sound source, it can be assumed that both oneself and others are listening to approximately the same sound. However, oneself and others listening together have completely different body shapes.
Therefore, due to the reflections and diffractions caused by the head and torso, the physical characteristics of sound waves reaching the eardrum vary for each individual.

However, under the above conditions, it is assumed that despite different body shapes, one is listening to approximately the same sound, so the auditory perception of each person compensates to recognize or perceive the changes in the physical characteristics of sound waves reaching the eardrum due to body shape differences as approximately the same sound.

In environments where sound is heard through earphones or headphones, since the sound is provided directly to the outer ear from the driver without coming from outside the body, the above assumption no longer holds.
In other words, even if the same earphones or headphones are used, it can no longer be said that others are listening to the same sound as oneself.

Therefore, to discuss the sound of earphones or headphones, it is necessary to know how the individual's body shape affects the sound waves coming from outside the body.
In the concept of one's own virtual sound environment, it is necessary to consider the physical effects that individual body shapes have on the sound coming from outside the body, so data measured on the individual's head and torso shape is used to optimize the sound presented in headphones or earphones.