Audio level information recording/management method and audio output level adjustment method

A machine-readable storage medium containing instructions for adjusting an output level of audio data, the instructions, when executed in a digital audio system, causing the system to:

• search a recording medium for an audio file requested to be played, the recording medium storing a plurality of audio files;
• check audio level information recorded in the searched audio file;
• and
• adjust an output level of audio data to be reproduced of the searched audio file responsive to the checked audio level information, wherein the audio file is separated into a header information area, an audio data information area, and a tag information area, wherein the audio level information is recorded in the tag information area and an audio level information flag is recorded in the header information, and wherein the instructions cause the system to:
• compare the checked audio level information with a predetermined reference level;
• adjust a gain of the audio data to be reproduced in accordance with the comparison result and an audio volume level set by a user;
• and
• amplify and output the audio data to be reproduced, at the adjusted gain, wherein the adjusting a gain comprises:
• calculating a ratio between the predetermined reference level, a current audio file, and a next audio file;
• and
• modifying the gain according to the ratio, wherein the predetermined reference level is an average audio level of audio files requested to be played.

A digital audio system, comprising:

• a recording device configured to store a plurality of audio files;
• a converter configured to convert an audio file read from the recording device into audio data to be reproduced;
• a controller configured to search the recording device for an audio file requested by a user to be played, check audio level information recorded in the searched audio file, and adjust an output level of audio data to be reproduced of the searched audio file according to the checked audio level information and a user set audio volume level;
• and
• an amplifier configure to amplify the converted audio data according to the adjusted output level and output the amplified audio data, wherein the controller is configured to compare the checked audio level information with a predetermined reference level and adjust the gain of the audio amplifier in accordance with the comparison result and a system audio volume level to adjust the output level of the audio data to be reproduced, and wherein the predetermined reference level is an average audio level of audio files requested to be played.