Unified Communications Microphone & Speaker System YVC-1000 White Paper Yamaha’s High-quality Sound Technologies Which Further Accelerate Remote Communications Issued in March, 2015 1
Unified Communications Microphone & Speaker System YVC-1000 White Paper Foreword Recent years have ushered in a genuine unified communications era. Advances in not only hardware based teleconference systems, but in PC software based web conference systems as well have elevated their performance, and along with the HD-like high definition images, an even higher quality of sound came to be sought.
Unified Communications Microphone & Speaker System YVC-1000 White Paper Purpose of This White Paper Yamaha has developed the YVC (Yamaha Voice Communication) series to update our company’s heretofore concepts and technologies for the unified communications era.
Unified Communications Microphone & Speaker System YVC-1000 White Paper Chapter 1 Overview of YVC-1000 Sound Processing The YVC-1000’s sound signal processing technologies actualize high-quality sound and pleasant communications via the six basic signal processing technologies in the diagram below, which are configured by two of Yamaha’s unique technologies that support them. (Figure 1-1) The details of signal processing features are described in chapter 2.
Unified Communications Microphone & Speaker System YVC-1000 White Paper Chapter 2 1. Roles and Capabilities of the Six Sound Processing Technologies Adaptive Echo Canceller 1.1 What is the adaptive echo canceller? The adaptive echo canceller is a function which eliminates the sounds on the microphone side that are generated from the speakers, and the echoes that the microphone picks up. 1.
Unified Communications Microphone & Speaker System YVC-1000 White Paper (Table 2-1) Applying measured data results to two indexes of L (echo for plus, loss for minus) and D (duration time of echo or loss) in the right table of Figure 2-1 derives the appropriate evaluation sections (A1 - G) in the left table. Finally A1 indicates the highest performance of the echo canceller. In view of the insertion loss, its performance is degraded in the sequence of A2, B, C and D.
Unified Communications Microphone & Speaker System YVC-1000 White Paper Data measuring method: In order to simulate the above communication image, the measuring was performed with the system configuration in Figure 2-2. * The above validation results were obtained using YVC-1000 firmware Ver.1.05. (Figure 2-2) 2. Noise Reduction 2.
Unified Communications Microphone & Speaker System YVC-1000 White Paper 2.2 Superiority of YVC-1000 The commercial conventional systems eliminate noise only when there is no voice. However, they are unable to eliminate noises which coexist with voices. If this is the case, the predecessor generally eliminates steady human voices and music sounds by regarding them as noises. In contrast, YVC-1000 can eliminate noises even if they coexist with voices.
Unified Communications Microphone & Speaker System YVC-1000 White Paper (Figure 2-3) 3. Automatic Gain Control 3.1 What is automatic gain control? Automatic gain control is a function for adjusting the voices to be sent from the communicating parties to a constant level by automatically controlling the gain depending on the level of individual picked-up voices. Additionally, this function is required to suppress unnecessary sounds such as noises and unusual sounds.
Unified Communications Microphone & Speaker System YVC-1000 White Paper 3.2 Superiority of YVC-1000 With commercial conventional systems since it is difficult to distinguish noises and low voices, it is hard to raise the volume of low voices. In regard to that, since YVC-1000 has raised the accuracy of voice determinations via HVAD, sounds can be firmly raised without low voices and noises being determined.
Unified Communications Microphone & Speaker System YVC-1000 White Paper (Figure 2-5) 4. Automatic Tracking 4.1 What is automatic tracking? Automatic tracking is a function whereas clear sound pickup is implemented that automatically tracks the speaker within a room, and focuses in on that voice. In addition, since it pick up the sounds of just human voices without responding to noises, it demonstrates its effectiveness when it is utilized in conferences held in noisy rooms with lots of people. 4.
Unified Communications Microphone & Speaker System YVC-1000 White Paper < Comparisons with commercial conventional systems and validations > Validation results: (Table 2-3) As indicated in the table, in comparison with commercial conventional systems the sound pickup level differentials are notable when there is noise insertion. In the keyboard noise zone, for example, YVC-1000 provided a sound pickup level of -55.3 dB with respect to -40.
Unified Communications Microphone & Speaker System YVC-1000 White Paper 5. Dereverberation 5.1 What is dereverberation? Dereverberation is a function to make human voices clear by eliminating the components that adversely affect vocal clarity (listenability) even if this system is used in a room subject to excessive natural reverb. 5.2 Superiority of YVC-1000 In the sounds that are picked up by the microphones, the component levels that have determined the reverberation components are dropped.
Unified Communications Microphone & Speaker System YVC-1000 White Paper (Graph 2-5) There are some differences depending upon the reverberation properties in the rooms, thus it is known that basically the reverberation times can be shortened by up to half. (Table 2-4) Data measuring method: In the configurations in Figure 2-7, the reverberation time calculated from the pickup signals was measured with a normal microphone (without dereverberation) and YVC-1000.
Unified Communications Microphone & Speaker System YVC-1000 White Paper 6. Automatic Room EQ 6.1 What is automatic room EQ? The automatic room EQ is a function which automatically responds to the acoustic properties of a room and applies equalization to the speakers to facilitate the listening of reproduced sounds. YVC-1000 uses voice signals during conversations, and can even make real-time and automatic adjustments, however the automatic acoustic adjustment functions (refer to 2) of 2.
Unified Communications Microphone & Speaker System YVC-1000 White Paper properly suppressed by the automatic room EQ. At these times, overall gain adjustments are performed so that the volume sensation itself does not change. Data measuring method: In the configuration as in Figure 2-8, voices before and after processing with the automatic room EQ were measured by turning it ON and OFF via the software. * The above validation results were obtained using YVC-1000 firmware Ver.1.05.
Unified Communications Microphone & Speaker System YVC-1000 White Paper Chapter 3 Two Unique Technologies to Enhance Six Sound Processing Capabilities 1. Human Voice Activity Detection (HVAD) 1.1 Outline and purpose HVAD is a technology which discerns whether or not human voices are included in voice signals that are picked up by YVC-1000. 1.2 Operations and mechanisms HVAD operates in the basic signal processing technologies in the three following functions to dramatically enhance accuracy.
Unified Communications Microphone & Speaker System YVC-1000 White Paper stabilized. Since human voices cannot be distinguished if there is no HVAD, the auto gain control might respond to abrupt or steady noises. For example, if this function responds to intermittent low sounds (e.g. from keyboard typing) while nobody is saying anything, then the sound level will be underestimated (recognized as a low voice), thereby significantly increasing the microphone gain.
Unified Communications Microphone & Speaker System YVC-1000 White Paper implemented, all of the YVC-1000’s acoustic settings are optimized via the reproduction of the measuring sounds. ● Adjustment with an external speaker connected This function is particularly useful when connecting an external speaker since the difference in delay between the external and built-in speakers and frequency response can be corrected. (Refer to 3) to 4) of 2.2 in Chapter 3.
Unified Communications Microphone & Speaker System YVC-1000 White Paper YVC-1000 sets an appropriate delay in sound from the built-in speakers in accordance with the measurement results to correct the differences in delay between the external and built-in speakers. This setting value is retained even if the power is turned off.
Unified Communications Microphone & Speaker System YVC-1000 White Paper Conclusion In chapter 2, the findings which validated the performance of each of the YVC-1000’s signal processing technologies, confirmed excellent performance in all of the acoustic elements that influence the actualization of smooth remote conference communications.
Unified Communications Microphone & Speaker System YVC-1000 White Paper 10-1, Nakazawa-cho, Naka-ku, Hamamatsu City, Shizuoka Prefecture, 430-8650 http://jp.yamaha.
