The so-called sound quality refers to the fidelity of the audio signal after transmission and processing. At present, the industry-recognized sound quality standard is divided into 4 levels, namely, digital CD-DA quality, its signal bandwidth is 10Hz~20kHz; FM radio quality, its signal bandwidth is 20Hz~15kHz; AM radio quality, its signal The bandwidth is 50Hz~7kHz; the voice quality of the telephone, its signal bandwidth is 200Hz~3400Hz. It can be seen that the sound quality of the digital compact disc is the highest, and the voice quality of the telephone is the lowest. In game music, high sound quality is also required. Let's take a look at how to judge the sound quality of game music with the editor.
1.
The method of game speech sound quality evaluation is subjective evaluation and objective evaluation. At present, subjective evaluation is commonly used, which is measured by subjective scoring (MOS), which is divided into the following five levels: 5 (excellent), no distortion is detected; 4 (good), distortion is just detected, but not annoying; 3 (medium) , Perceive distortion, slightly annoying; 2 (bad), annoying, but not offensive; 1 (bad), extremely annoying, offensive. Generally speaking, if the reproduced speech frequency is above 7kHz, MOS can be rated as 5 points.
2. The sound quality of
game music The sound quality of game music depends on many factors, such as sound source characteristics (sound pressure, frequency, spectrum, etc.), signal characteristics of audio equipment (such as distortion, frequency response, dynamic range, signal-to-noise ratio) , Transient characteristics, stereo separation, etc.), sound field characteristics (such as direct sound, early reflections, reverberation, inter-aural correlation, reference vibration, sound absorption, etc.), auditory characteristics (such as loudness curve, audible Range, various senses of hearing), etc.
A summary of the evaluation methods of game music sound quality is as follows:
(1) Subjective listening and judging sound effects
Generally, the three elements of game music sound quality, namely the changes and combinations of loudness, pitch and pleasantness, are used to subjectively evaluate various attributes of sound quality, such as low frequency loudness as sound Fullness, loud high frequency means bright sound, weak low frequency means smooth sound, weak high frequency means clear sound.
(2) Objective test technical indicators—distortion.
Harmonic distortion mainly causes the sound to become hard and exploded; while the steady-state or transient intermodulation distortion mainly causes the sound to be rough, sharp and turbid. Both degrade the sound quality, and if the distortion exceeds 3%, the sound quality deteriorates significantly. The speaker of the audio system has the largest distortion, and the minimum distortion generally exceeds 1%.
Phase distortion mainly causes the low frequency sound below 1kHz to be blurred, and at the same time affects the intermediate frequency sound level and sound image localization.
Shaking distortion is mainly caused by unstable motor speed, instability of pressure on the capstan-pinch roller, and tape vibration and tape volume change caused by the head beating on the tape, which in turn modulates the signal frequency, and the voice tone appears muddy and trembling.
In game music, if the sound quality is too high, the equipment is complicated; otherwise, it cannot meet the application. Generally, the principle is "enough without waste".