Audio Signal Compression Technology: A Frequency Domain Perspective

# 1. An Overview of Audio Signal Compression Technology

## 1.1 Definition and Significance of Audio Signal Compression

Audio signal compression is a technique that reduces the amount of data required to represent a signal by decreasing the number of bits. In modern digital communication and media applications, due to the contradiction between the storage and transmission requirements of high-fidelity audio data and the limited bandwidth and storage resources, ***pression can effectively reduce file size, improve transmission efficiency, and save storage space while maintaining high audio quality.

## 1.2 Common Audio Compression Algorithms and Their Features

Currently, common audio compression algorithms include lossless and lossy compression. Lossless compression algorithms can fully restore the original audio signal, such as FLAC, APE, etc.; lossy compression algorithms discard a certain amount of information during the compression process, but can reduce the file size more significantly, such as MP3, AAC, etc. These algorithms have different characteristics in terms of compression ratio, audio quality loss, and real-time performance, and the appropriate algorithm can be selected based on actual needs.

## 1.3 The Application of Frequency Domain Compression Technology in Audio Processing

Frequency domain compression technology is a method of compression processing based on the spectral characteristics of the signal, which achieves effective compression of the signal by analyzing and processing the frequency spectrum of the audio signal. Frequency domain compression technology is widely used in audio coding and decoding, real-time communication, music production, and other fields, enabling efficient data compression while ensuring audio quality to some extent.

# 2. Fundamentals of Frequency Domain Analysis

Frequency domain analysis is a method of studying and analyzing the characteristics of a signal in the frequency domain (frequency domain), which is of great significance in audio signal processing. This chapter will introduce the basic knowledge of frequency domain analysis, including the basic concepts and principles of frequency domain analysis, Fourier transform and spectrum analysis, as well as frequency domain filtering and frequency domain sampling techniques.

### 2.1 Basic Concepts and Principles of Frequency Domain Analysis

In frequency domain analysis, the characteristics of a signal are described by changes in frequency, rather than changes over time in the time domain. The basic principle of frequency domain analysis is to decompose a signal into sine wave components of different frequencies, and by analyzing the amplitude, phase, and other information of these frequency components, the frequency domain characteristics of the signal can be revealed.

### 2.2 Fourier Transform and Spectrum Analysis

The Fourier transform is the basic tool of frequency domain analysis, which can convert a signal from the time domain to the frequency domain. Through the Fourier transform, we can obtain the spectrum of the signal, that is, the representation of the signal in the frequency domain. Spectrum analysis can help us understand the frequency domain characteristics of the signal, including the strength of frequency components, frequency distribution, and other information.

### 2.3 Frequency Domain Filtering and Frequency Domain Sampling Techniques

Frequency domain filtering utilizes the results of frequency domain analysis to filter the signal, which can enhance or suppress specific frequency components. Frequency domain filtering is often used in applications such as audio noise reduction and signal enhancement. Frequency domain sampling technology samples the frequency domain signal, usually combined with compression algorithms for the compression and storage of audio signals.

Through the study of frequency domain analysis, we can better understand the characteristics of audio signals in the frequency domain and provide a foundation and methods for subsequent audio signal compression technology.

# 3. Frequency Domain Feature Analysis of Audio Signals

Frequency domain feature analysis of audio signals is the process of analyzing and describing audio signals in the frequency domain to reveal information about the frequency distribution, spectral characteristics, and frequency domain correlation of audio signals. Frequency domain analysis plays an important role in audio processing, helping to understand the structure and characteristics of audio