• Title/Summary/Keyword: audio frequency

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Frequency-Temporal Filtering for a Robust Audio Fingerprinting Scheme in Real-Noise Environments

  • Park, Man-Soo;Kim, Hoi-Rin;Yang, Seung-Hyun
    • ETRI Journal
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    • v.28 no.4
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    • pp.509-512
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    • 2006
  • In a real environment, sound recordings are commonly distorted by channel and background noise, and the performance of audio identification is mainly degraded by them. Recently, Philips introduced a robust and efficient audio fingerprinting scheme applying a differential (high-pass filtering) to the frequency-time sequence of the perceptual filter-bank energies. In practice, however, the robustness of the audio fingerprinting scheme is still important in a real environment. In this letter, we introduce alternatives to the frequency-temporal filtering combination for an extension method of Philips' audio fingerprinting scheme to achieve robustness to channel and background noise under the conditions of a real situation. Our experimental results show that the proposed filtering combination improves noise robustness in audio identification.

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High Frequency Enhancement of Sound Using Wavelet Transform

  • Yoon Won-Jung;Lee Kang-Kyu;Park Kyu-Sik
    • Proceedings of the IEEK Conference
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    • summer
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    • pp.233-236
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    • 2004
  • This paper proposes new method for the enhancement of nonexistent high frequency spectral contents from low sample rate audio signal. For example, Due to the protocol constraint, the audio bandwidth of MP3 is restricted to 16Khz. Although band-restricted MP3 audio provide savings of storage space and network bandwidth, it suffers a major problem of a loss in high frequency fidelity such as localization, ambient information, and bright nature of audio. This paper provides a new mathematical analysis for the adaptive estimation of the high frequency contents based on the nature of the input low sample rate audio. Proposed method can be worked globally to any kind of audio such as speech and music that are restricted by sampling rate and bandwidth.

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Sound Enhancement of low Sample rate Audio Using LMS in DWT Domain (DWT영역에서 LMS를 이용한 저 샘플링 비율 오디오 신호의 음질 향상)

  • 백수진;윤원중;박규식
    • The Journal of the Acoustical Society of Korea
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    • v.23 no.1
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    • pp.54-60
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    • 2004
  • In order to mitigate the problems in storage space and network bandwidth for the full CD quality audio, current digital audio is always restricted by sampling rate and bandwidth. This restriction normally results in low sample rate audio or calls for the data compression scheme such as MP3. However, they can only reproduce a lower frequency range than a regular CD quality because of the Nyquist sampling theory. Consequently they lose rich spatial information embedded in high frequency. The propose of this paper is to propose efficient high frequency enhancement of low sample rate audio using n adaptive filtering and DWT analysis and synthesis. The proposed algorithm uses the LMS adaptive algorithm to estimate the missing high frequency contents in DWT domain and it then reconstructs the spectrally enhanced audio by using the DWT synthesis procedure. Several experiments with real speech and audio are performed and compared with other algorithm. From the experimental results of spectrogram and sonic test, we confirm that the proposed algorithm outperforms the other algorithm and reasonably works well for the most of audio cases.

An Implementation of an ARM Platform based MP3 Sound Enhancement System (ARM 플랫폼 기반의 MP3 오디오 음질 향상 시스템 구현)

  • Oh, Sang-Hun;Park, Kyu-Sik
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.44 no.1
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    • pp.70-75
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    • 2007
  • In order to mitigate the problems in storage space and network bandwidth for the full CD quality audio with 44.1 kHz sampling rate, current existing digital audio is always restricted by sampling rate and bandwidth. This kind of restriction normally can be resolved by using low bit rate audio codec such as MP3, OGG, and AAC. However it suffers a major problem such as a loss of high frequency fidelity. This high frequency loss will reproduce only the band-limited low-frequency part of audio in the standard CD-quality audio. In general, the high frequency contents of audio have lots of information such as localization and ambient information, and bright nature of audio. The purpose of this paper is to implement on ARM platform system that can effectively estimate and compensate the missing high frequency contents of MP3 audio. From the experimental results with spectrum analysis and listening test, we confirm the superiority of the proposed algorithms for MP3 audio quality enhancement.

A Study on the Audio watermarking for High Quality Digital Audio (고음질 오디오를 위한 디지털 오디오 워터마킹에 관한 연구)

  • 김정태;구대성;이강현
    • Proceedings of the IEEK Conference
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    • 2000.06c
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    • pp.125-128
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    • 2000
  • In this paper, we proposed the high quality digital audio watermarking algorithm in the frequency domain. The spread spectrum technique is used to encrypted a stream of information by spreading the data as much of the frequency spectrum as possible. It's technique adapt well to data hiding in audio signal. We have used the perceptual model and MDCT/IMDCT for the high qualify digital audio watermarking. The proposed watermark algorithm preserved high quality audio data from watermark signal.

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An Audio Watermarking Technique Using BPSK with Variable Carrier Frequency (가변 반송파 BPSK를 이용한 오디오 워터마킹 기법)

  • 이형욱;박세형;문용민;한상우;신재호
    • Proceedings of the IEEK Conference
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    • 2000.06d
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    • pp.110-113
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    • 2000
  • In this paper, we consider the problem of digital audio watermarking to robust about compression without original audio data. We specifically address the audio watermarking using BPSK with variable carrier frequency. This technique make audio data embeded watermarking robust with compression attack, for example MPEG, AC-3, etc.

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A Study on the Improvement of Test and Diagnosis Device for Audio Frequency Track Circuit (가청주파수 궤도회로의 진단 및 시험 장비 개선에 대한 연구)

  • Kang, Jang-Kyu;Kim, Jae-Chul
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.24 no.12
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    • pp.147-155
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    • 2010
  • We studied on performance improvement of TTM(TI21 Test Meter) that is test and diagnosis devices for jointless audio frequency track circuit on Korean electric railway TI21 standard. Upgraded devices is AD-TTM(Advanced TI21 Test Meter). This can measure alternating frequency USB(Upper signal band) and LSB(Lower signal band). In the audio frequency track circuit, ${\pm}17[Hz]$ of nominal frequency are demodulated and supplied to track relay through AND gate. It is important that measurement function which is error between USB and LSB. Need of AD-TTM will stand out in the electric railway system because this is simple and accurate rather than the former device.

Implementation of an Ultrasonic Modem Providing Low Cost Communication Channel in the Audio Frequency Boundary Band (가청주파수 경계대역에서 저가의 통신채널을 제공하는 초음파 모뎀 구현)

  • Jeon, Seong-Bae;Lee, Dong-Won;Chung, Hae
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.6
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    • pp.1391-1396
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    • 2010
  • Recently, communication components prefer Bluetooth or Zigbee for PAN. However, using these makes expensive and complicated products such as audio equipments, mobile phones, PC, etc. for transmitting simple messages with low rate. In this paper, we propose wireless communication method using ultrasonic in the audio frequency limit band with speakers and microphones which are in products. We suggest transmitting and receiving methods in the audio frequency limit band for transmitting data without affecting audio signal, and implement an ultrasonic communication modem. Finally, we verify the performance of the ultrasonic communication modem by experiments in an environment with background noise.

Implementation of an Ultrasonic Modem in the Audio Frequency Limit Band for Low Cost Communication Channel (저가의 통신채널 확보를 위한 가청주파수 한계대역에서의 초음파 모뎀 구현)

  • Jeon, Seong-Bae;Lee, Dong-Won;Chung, Hae
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2010.05a
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    • pp.109-112
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    • 2010
  • Recently, communication components prefer Bluetooth or Zigbee for PAN. However, using these makes expensive and complicated products such as audio equipments, mobile phones, PC, etc. for transmitting simple messages with low rate. In this paper, we propose wireless communication method using ultrasonic in the audio frequency limit band with speakers and microphones which are in products. We suggest transmitting and receiving methods in the audio frequency limit band for transmitting data without affecting audio signal, and implement an ultrasonic communication modem. Finally, we verify the performance of the ultrasonic communication modem by experiments in an environment with background noise.

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ZVT-PWM Amplifier for Audio Applications (소프트 스위칭 기술을 이용한 오디오용 파워앰프)

  • Seo, D.H.;Cho, B.H.
    • Proceedings of the KIEE Conference
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    • 1998.07f
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    • pp.2145-2147
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    • 1998
  • This paper presents a Class-D type switched mode audio power amplifier employing ZVT(Zero-Voltage-Transition) soft switching technique. In order to obtain a wide bandwidth and lower distortion for an audio amplifier a high switching frequency is essential. The ZVT switching scheme enables a high frequency switching without sacrificing the efficiency much as in a hard switching. A prototype amplifier is built to demonstrate the feasibility of this technique for the audio power amplifier.

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