Appendix: Information sources & further reading
note: besides references to scientific publications, this reference list includes references to Wikipedia. Although the information in the Wikipedia lemma’s is not guaranteed to be consistent, it provides a very accessible source of information - with further references at the bottom of each article. As a thank you, the author has made a financial contribution to Wikipedia.org.
references in chapter 1: Audio Quality
1A | Quality | Quality is free, Phill B. Crosby, ISBN0070145121, McGraw-Hill, Inc. |
references in chapter 4: The human auditory system
4C | outer hair cells | Auditory neuroscience, Schnupp et al, P73. Also: http://en.wikipedia.org/wiki/Hair_cell (Outer hair cells - acoustic pre-amplifiers) |
4D | cochlear nerve | http://en.wikipedia.org/wiki/Cochlear_nerve (anatomy and connections) |
4E | hair cells | Fundamentals of Hearing,m W.A. Yost, p88. also: http://en.wikipedia.org/wiki/Auditory_system (hair cell) |
4F | neurons | http://en.wikipedia.org/wiki/Cochlear _nerve (types of neurons) |
4G | equal loudness contour ISO226 | http://en.wikipedia.org/wiki/Equal_loudness_contour |
4H | Tinitus | http://en.wikipedia.org/wiki/Tinitus (pathophysiology) |
4I | hearing damage | directive 2003/10/EC of the European Parliament and of the Council of 6 Februari 2003 http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2003:042:0038:0044:EN:PDF |
ISO1990:1999 | can be purchased from ISO.ORG. | |
4J | threshold of pain | http://en.wikipedia.org/wiki/Threshold_of_pain |
4K | Kunchur papers | http://www.physics.sc.edu/~kunchur/papers/Audibility-of-time-misalignment-of-acousticsignals--- Kunchur.pdf and http://www.physics.sc.edu/~kunchur/papers/Temporal-resolution-by-bandwidth-restriction--Kunchur.pdf |
4L | echoic memory | http://en.wikipedia.org/wiki/Echoic_memory (Overview) |
4M | neuron connectivity | http://en.wikipedia.org/wiki/Neuron (connectivity) |
4N | simplified auditory processing model | based on ‘Binaural signal processing’, Jens Blauert & Jonas Braash, Ruhr university, Bochum, Germany. pdf available at IEEEXplore.ieee.org |
4O | Barkhausen, phon, bark | Fastl & Zwicker, Psychoacoustics http://en.wikipedia.org/wiki/Bark_scale |
4P | masking | Fastl & Zwicker, Psychoacoustics http://en.wikipedia.org/wiki/Auditory_masking (similar frequencies) |
4Q, R | sharpness, roughness | Fastl & Zwicker, Psychoacoustics |
4S | localization | Auditory neuroscience, Jan Schnupp, chapter 5 |
4T | Haas effect | http://en.wikipedia.org/wiki/Haas_effect |
4U | AFC | reference needed |
4V | visual environment | Hearing lips and seeing voices, McGurk H., MacDonald J. Nature 264 (1976): p746–p748. pdf available at www.nature.com also: http://en.wikipedia.org/wiki/Sound_localization |
4R | auditory masking | http://en.wikipedia.org/wiki/Auditory_masking (similar frequencies) |
references in chapter 5: sampling
5A | carbon microphone | http://en.wikipedia.org/wiki/Carbon_microphone |
5B | Victor Orthophonic Victrola | http://en.wikipedia.org/wiki/Victor_Orthophonic_Victrola |
5C | Magnetophon | http://en.wikipedia.org/wiki/Magnetophon |
5D | Compact Cassette | http://en.wikipedia.org/wiki/Compact_cassette |
5E | PCM | http://en.wikipedia.org/wiki/Pulse-code_modulation |
5F | CD | http://en.wikipedia.org/wiki/Compact_disc |
5I | analogue mixer specifications | users manual specifications & specifications sheets: Midas XL4: www.midasconsoles.com |
5J | A/D converter | http://en.wikipedia.org/wiki/Analog-to-digital_converter |
5K | MAC operation | http://en.wikipedia.org/wiki/Multiply–accumulate_operation |
5L | 6dB per bit | Taking the Mystery out of the Infamous Formula, “SNR = 6.02N + 1.76dB,” http://www.analog.com/static/imported-files/tutorials/MT-001.pdf |
5M | dither | http://en.wikipedia.org/wiki/Dither |
5N | dynamic range of digital systems | users manual specifications & specification sheets DigiCo SD8: www.digiconsoles.com Avid SC48: www.avid.com |
5O | Nyquist-Shannon | http://en.wikipedia.org/wiki/Nyquist–Shannon_sampling_theorem |
5P | oversampling | http://en.wikipedia.org/wiki/Oversampling |
5Q | speed of electricity | http://en.wikipedia.org/wiki/Speed_of_electricity |
5R | analog switch data sheet | Datasheet 74HC4053 |
5S | jitter | Jitter: specification and assessment in digital audio equipment, Julian Dunn, Cambridge presentation AES 93rd convention, 1992. Available through www.aes.org |
5T | PTP | http://en.wikipedia.org/wiki/Precision_Time_Protocol |
5U | sinusoidal jitter audibility | Theoretical and Audible Effects of Jitter on Digital Audio Quality, Eric Benjamin and Benjamin Gammon, Dolby Laboraties inc presentation AES 105th convention, 1998. Available through www.aes.org |
5V | noise shaped jitter audibility | Detection threshold for distortions due to jitter on digital audio, Kaori Ashihara, Shogo Kiryu et al, National Institute of Advanced Industrial Science and Technology - Acoustical Science and Technology 26, 1 (2005) |
references in chapter 6: distribution & DSP
6A | Dante 32-bit | http://dev.audinate.com/kb/webhelp/content/yamaha/clseries/the_yamaha_cl_series_consoles_and_io_racks_use__the_new_dante_32-bit_mode_of_operation_.htm |
6B | Moore’s law | http://en.wikipedia.org/wiki/Moore’s_law |
6C | Native | http://en.wikipedia.org/Native_processing |
6D | Motorola 56K series | http://en.wikipedia.org/wiki/Motorola_56000 |
6E | Analog Devices SHARC | Analog Devices - getting started with SHARC, http://www.analog.com/static/imported-files/tech_docs/GettingStartedwithSharcProcessors.pdf |
6F | Texas Instruments | http://ti.com/lsds/ti/dsp/c6000_dsp/c674x/products.page |
references in chapter 7: level issues
7A | AES2 1984 (R2003) | available through www.aes.org |
references in chapter 8: operational quality issues
8A | Optocore | http://www.optocore.com/downloads/pdf/Optocore_Basics_cabling.pdf |
8B | Riedel Rocknet | http://www.riedel.net/AudioSolutions/RockNetOverview/AboutRockNet/tabid/502/language/ en-US/Default.aspx |
8C | EtherSound | http://www.EtherSound.com/ |
8D | CobraNet | http://www.cobranet.info/ |
8E | Dante | http://www.audinate.com/index.php?option=com_content&view=article&id=93&Itemid=93 |
8F | audio networks | ‘an introduction to networked audio systems’, Ron Bakker, Introduction to Networked Audio |
8G | AVB | http://en.wikipedia.org/wiki/Audio_Video_Bridging |
8H | Cobranet system design EtherSound system design |
‘networked audio system design with CobraNet’ ‘networked audio system design with EtherSound’ |
8I | Neutrik Ethercon | http://www.neutrik.com/en/ethercon/ |
8J | Neutrik opticalcon | http://www.neutrik.com/en/opticalcon/ |
8K | Connex Fiberfox | http://www.fiberfox.com/fiberfox_ebene.htm |
references in chapter 9: quality assessment methods
9A | audio quality assessment | understanding what really matters with audio reproduction and what not’, Ethan Winer, workshop AES 38th convention 2009, available through www.aes.org |
9B | translation of listening tests | measurement and perception of quality in sound systems, G.R. Thurmond,11th AES international convention 1992, available through www.aes.org |
9C | sighted listening | Hearing is believing vs. Believing is Hearing: Blind vs. Sighted Listening Tests, and Other Interesting Things, Floyd E. Toole and Sean E. Olive, Harman International Industries, Inc. international convention 1997, pdf available at www.aes.org |
further reading:
books:
white papers and technical publications:
an introduction to networked audio systems, Yamaha | Introduction to Networked Audio |
networked audio system design with CobraNet, Yamaha | Networked Audio System Design with CobraNet |
networked audio system design with EtherSound, Yamaha | Networked Audio System Design with ES100 |
Chapter 1 - Audio Quality
Presents a set of definitions and requirements. To support meaningful discussions on audio quality, the concepts ‘quality’, ‘audio’ and ‘sound’ are defined in detail.
1.1 Audio
1.2 Sound
1.3 Audio processes
1.4 Quality
1.5 Audio quality
1.6 Sound quality
1.7 Discussing audio quality
Chapter 2 - Networked audio systems
Presents a description of a typical networked (and therefore digital) audio system. The described system is modular, supported by networking technologies that have become common practise in the professional audio field.
2.1 Audio processes
2.2 Audio formats
2.3 Audio system components
Chapter 3 - Performance & Response
Presents the Performance / Response concept - identifying system process parameters and requirements to help assessing the quality of audio systems. Two design philosophies are presented: ‘natural sound’ - where the focus lies on preserving the artistic quality of the audio event and offering Response tools to the sound engineer as variable parameters, and ‘coloured sound’ where a fixed sound-changing Response is designed into products and systems.
3.1 Unintended and Intended changes
3.2 Performance & Response
3.3 Natural sound and coloured sound
Chapter 4 - The human auditory system
Briefly presents a description of the human auditory system, including the mechanics of the outer and middle ear, the bio-mechanical coding to the frequency domain by the inner ear, and the transport of the coded firing patterns to the brain through auditory nerves. Using this description, a ‘human audio universe’ is defined to possess three dimensions: level, frequency and time. Also some auditory functions such as localization and masking are presented.
4.1 Ear anatomy
4.2 The audio universe
4.3 Auditory functions
Chapter 5 - Sampling issues
Presents the audio digitalization (sampling) concept in relation to level, frequency and timing. Dynamic range and frequency range are more or less common concepts, developed to a mature state by the manufacturers of digital audio equipment in the past 25 years. Compared with the 1985 digital (16-bit) technologies, modern 24-bit A/D, D/A and distribution technologies and 32-bit or higher DSP architecture have caused noise floors and distortion levels to move close the boundaries of the audio universe. On timing however, the use of networked audio systems pose new challenges to system designers and sound engineers. This chapter presents the digitalization concept in relation to timing, including latency, jitter and clock phase.
5.1 Digital Audio
5.2 Dynamic range
5.3 Frequency range
5.4 Timing issues
5.5 Absolute latency
5.6 Relative latency
5.7 Word clock
5.8 Clock phase
5.9 Temporal resolution
5.10 Jitter
Chapter 6 - Distribution & DSP issues
Presents a description of the transport and DSP infrastructure in a digital audio system. Transport and DSP architecture - eg. bit depth, fixed/floating point processing - are described to have an effect on a system’s audio quality, with only the algorithm (plug-in) design to affect the system’s sound quality.
6.1 I/O distribution
6.2 Interconnected DSP distribution
6.3 Constant gain A/D converters
6.4 DSP architecture
6.5 Fixed point vs. Floating point
6.6 DSP user interfaces
Chapter 7 - Signal chain level issues
Focuses on audio levels in a system, proposing a ‘0dBFS’ level standard as the optimal design paradigm that allows easy identification of quality problems in a signal chain. Several practical quality issues in system design are presented, such as head amps, gain compensation, clip level mismatch, double pass signal chains. Also, audio compression in speaker processing stage (unbalanced output modes) is discussed, placing the responsibility in the Response (sound quality) domain rather than the Performance (audio quality) domain.
7.1 0dBFS
7.2 Head amps
7.3 Gain compensation
7.4 Clip level mismatch
7.5 Double A/D-D/A pass signal paths
7.6 Unbalanced output mode
Chapter 8 - operational quality
Presents operational quality issues in a networked audio environment, including topology and protocol and their effect on logistics, reliability and redundancy. The use of ethernet - either as protocol or as embedded service - is posed to be of essential importance to comply with operational quality requirements on design freedom and user interfacing.
8.1 Network implications
8.2 Ethernet compliance
8.3 Redundancy
8.4 Switches and cables
Chapter 9 - quality assessment methods
Presents methods for subjective and objective quality assessments of audio systems. Conditions for controlled listening tests are proposed for audio quality assessment. Full control over the experiments with careful adjustment of test equipment and environment, and proper statistical analysis are crucial to obtain meaningful results that justify statements on product and system audio quality and Response characteristics.
9.1 Quality assessment through electronic measurements
9.2 Quality assessment through listening tests
9.3 Conducting listening tests
Appendix
Lists information sources and further reading suggestions.
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