Wideband Audio
Encyclopedia
Wideband audio is an audio technology used in telephony. It extends the frequency range of audio signals transmitted over telephone lines, resulting in higher quality speech. The range of the human voice
extends from 80 Hz to 14 kHz but traditional, voiceband
or narrowband
telephone calls limit audio frequencies to the range of 300 Hz to 3.4 kHz. Wideband audio relaxes the bandwidth limitation and transmits in the audio frequency
range of 50 Hz to 7 kHz or higher.
In 1987, the International Telecommunication Union
(ITU) standardized a version of wideband audio as G.722
. Radio broadcasters began using G.722 over Integrated Services Digital Network
(ISDN) to provide high-quality audio for remote broadcast
s, such as from sports venues.
The traditional telephone network (PSTN) is generally limited to narrowband audio by the intrinsic nature of its transmission technology, TDM (Time-Division Multiplexing
), and by the analogue-to-digital converters used at the edge of the network, as well as the speakers, microphones and other elements in the endpoints themselves.
Wideband audio has been broadly deployed in conjunction with video conferencing. Providers of this technology quickly discovered that despite the explicit emphasis on video transmission, the quality of the participant experience was significantly influenced by the fidelity of the associated audio signal.
Communications via Voice over Internet Protocol (VoIP) can readily employ wideband audio. When PC-to-PC calls are placed via VoIP services, such as Skype
, and the participants use a high-quality headset, the resulting call quality can be noticeably superior to conventional PSTN calls. Some of the handset manufactured by Nokia which run S60 and Series40 OS that support VoIP also support wideband audio. A number of audio codecs have emerged to support these services, supplementing G.722.
Manufacturers of audio conferencing equipment have introduced wideband-capable models that include support for G.722 over VoIP.
Conference calls are a direct beneficiary of the enhancements offered by wideband audio. Participants often struggle to figure out who is talking, or to understand accented speakers. Misunderstandings are commonplace due primarily to generally poor audio quality and an accumulation of background noise.
Some listener benefits cited of wideband audio compared to traditional (narrowband):
Despite its reputation for poor audio quality, the mobile telephone industry has started to make some progress on wideband audio. The 3GPP
standards group has designated G.722.2 as its wideband codec and calls it Advanced Multirate – Wideband (AMR-WB
). A few handsets have been produced supporting this codec (for example, Nokia
), and network demonstrations have been conducted.
, Cisco
, Grandstream, Gigaset, Polycom
(which brands wideband audio "HD Voice"), Snom
, AudioCodes
(which brands wideband audio "HDVoIP") and others now incorporate G.722
, as well as varying degrees of higher-quality audio components.
Suppliers of integrated circuits for telephony equipment, including Broadcom
, Infineon, and Texas Instruments
, include wideband audio in their feature portfolios.
There are audio conferencing service providers that support wideband connections from these and other VoIP endpoints, while also permitting PSTN participants to join the conference in narrowband. sipXtapi is an open source solution for VoIP media processing engine supporting wideband and HD voice that provides RTP and codecs through a plugin framework for use with SIP and other VoIP protocols. Skype
uses an audio codec called Silk
which allows for extremely high quality audio.
A number of carriers around the world have rolled out HD voice services based on the G.722 wideband standard. In North America, hosted service providers have recently deployed the Aastra Hi-Q upgrade to its installed user base and as of January 2010 claimed around 70,000 HD voice endpoints. Consumer service provider ooma has an estimated 25,000 HD voice endpoints deployed stemming from its roll out of its second-generation Telo hardware.
After years of trials, AMR-WB was made commercially available in September 2009, when Orange
launched the world's first high-definition voice service for mobile phones in Moldova
, the first time since the 1990s that mobile voice technologies have been subject to a significant evolution. The first mobile handset integrating high-definition voice capability launched by Orange Moldova
is the Nokia 6720
c, which integrates WB-AMR. Orange has since rolled out HD voice in the UK, France
, Belgium
, Romania
, Armenia
, Dominican Republic
and Catalonia
, with Switzerland
and Luxembourg
due to follow.
Three UK launched HD voice calls onto their network at the end of May 2011.
Human voice
The human voice consists of sound made by a human being using the vocal folds for talking, singing, laughing, crying, screaming, etc. Its frequency ranges from about 60 to 7000 Hz. The human voice is specifically that part of human sound production in which the vocal folds are the primary...
extends from 80 Hz to 14 kHz but traditional, voiceband
Voiceband
In electronics, voiceband means the typical human hearing frequency range that is from 20 Hz to 20 kHz. In telephony, it means the frequency range normally transmitted by a telephone line, generally about 200–3600 Hz. Frequency-division multiplexing in telephony normally uses...
or narrowband
Narrowband
In radio, narrowband describes a channel in which the bandwidth of the message does not significantly exceed the channel's coherence bandwidth. It is a common misconception that narrowband refers to a channel which occupies only a "small" amount of space on the radio spectrum.The opposite of...
telephone calls limit audio frequencies to the range of 300 Hz to 3.4 kHz. Wideband audio relaxes the bandwidth limitation and transmits in the audio frequency
Audio frequency
An audio frequency or audible frequency is characterized as a periodic vibration whose frequency is audible to the average human...
range of 50 Hz to 7 kHz or higher.
In 1987, the International Telecommunication Union
International Telecommunication Union
The International Telecommunication Union is the specialized agency of the United Nations which is responsible for information and communication technologies...
(ITU) standardized a version of wideband audio as G.722
G.722
G.722 is a ITU-T standard 7 kHz wideband speech codec operating at 48, 56 and 64 kbit/s. It was approved by ITU-T in November 1988. Technology of the codec is based on sub-band ADPCM ....
. Radio broadcasters began using G.722 over Integrated Services Digital Network
Integrated Services Digital Network
Integrated Services Digital Network is a set of communications standards for simultaneous digital transmission of voice, video, data, and other network services over the traditional circuits of the public switched telephone network...
(ISDN) to provide high-quality audio for remote broadcast
Remote broadcast
In broadcast engineering, a remote broadcast is broadcasting done from a location away from a formal television studio and is considered an electronic field production . A remote pickup unit is usually used to transmit the audio and/or video back to the television station, where it joins the...
s, such as from sports venues.
The traditional telephone network (PSTN) is generally limited to narrowband audio by the intrinsic nature of its transmission technology, TDM (Time-Division Multiplexing
Time-division multiplexing
Time-division multiplexing is a type of digital multiplexing in which two or more bit streams or signals are transferred apparently simultaneously as sub-channels in one communication channel, but are physically taking turns on the channel. The time domain is divided into several recurrent...
), and by the analogue-to-digital converters used at the edge of the network, as well as the speakers, microphones and other elements in the endpoints themselves.
Wideband audio has been broadly deployed in conjunction with video conferencing. Providers of this technology quickly discovered that despite the explicit emphasis on video transmission, the quality of the participant experience was significantly influenced by the fidelity of the associated audio signal.
Communications via Voice over Internet Protocol (VoIP) can readily employ wideband audio. When PC-to-PC calls are placed via VoIP services, such as Skype
Skype
Skype is a software application that allows users to make voice and video calls and chat over the Internet. Calls to other users within the Skype service are free, while calls to both traditional landline telephones and mobile phones can be made for a fee using a debit-based user account system...
, and the participants use a high-quality headset, the resulting call quality can be noticeably superior to conventional PSTN calls. Some of the handset manufactured by Nokia which run S60 and Series40 OS that support VoIP also support wideband audio. A number of audio codecs have emerged to support these services, supplementing G.722.
Manufacturers of audio conferencing equipment have introduced wideband-capable models that include support for G.722 over VoIP.
Conference calls are a direct beneficiary of the enhancements offered by wideband audio. Participants often struggle to figure out who is talking, or to understand accented speakers. Misunderstandings are commonplace due primarily to generally poor audio quality and an accumulation of background noise.
Some listener benefits cited of wideband audio compared to traditional (narrowband):
- Clearer overall sound quality
- Easier to recognize voices, distinguish confusing sounds and understand accented speakers
- Ease of deciphering words that have the close sounds of ‘s’ and ‘f’ and others, often indistinguishable over telephone lines.
- Ability to hear faint talkers and to understand double-talk (when more than one person is speaking at the same time)
- Reduced listening effort (decreased cognitive load), resulting in increased productivity and lessened listener fatigue
- Better understanding in the face of other impairments, such as when talkers are using a speakerphone or in the presence of background noise
Despite its reputation for poor audio quality, the mobile telephone industry has started to make some progress on wideband audio. The 3GPP
3GPP
The 3rd Generation Partnership Project is a collaboration between groups of telecommunications associations, known as the Organizational Partners...
standards group has designated G.722.2 as its wideband codec and calls it Advanced Multirate – Wideband (AMR-WB
AMR-WB
Adaptive Multi-Rate Wideband is a patented speech coding standard developed based on Adaptive Multi-Rate encoding, using similar methodology as Algebraic Code Excited Linear Prediction...
). A few handsets have been produced supporting this codec (for example, Nokia
Nokia
Nokia Corporation is a Finnish multinational communications corporation that is headquartered in Keilaniemi, Espoo, a city neighbouring Finland's capital Helsinki...
), and network demonstrations have been conducted.
Deployment
As business telephone systems have adopted VoIP technology, support for wideband audio has grown rapidly. Telephone sets from AvayaAvaya
Avaya Inc. is a privately held computer networking, information technology and telecommunications company that is a global provider of business communications systems. The international head quarters is in Basking Ridge, New Jersey, United States...
, Cisco
Cisco
Cisco may refer to:Companies:*Cisco Systems, a computer networking company* Certis CISCO, corporatised entity of the former Commercial and Industrial Security Corporation in Singapore...
, Grandstream, Gigaset, Polycom
Polycom
Polycom is a multinational corporation with approximately 3,200 employees worldwide and an annual revenue of approximately $1.2 billion in 2010. The company manufactures and sells telepresence and voice communications solutions.-Company History 1990:...
(which brands wideband audio "HD Voice"), Snom
Snom
snom Technology AG is a German company which manufactures Voice over Internet Protocol telephones, based on the IETF standard Session Initiation Protocol...
, AudioCodes
AudioCodes
AudioCodes Ltd. designs, develops, and sells products for voice, data, and video over IP networks. The company is an early pioneer of the VoIP industry having shipped VoIP solutions as early as 1995.-Company history:...
(which brands wideband audio "HDVoIP") and others now incorporate G.722
G.722
G.722 is a ITU-T standard 7 kHz wideband speech codec operating at 48, 56 and 64 kbit/s. It was approved by ITU-T in November 1988. Technology of the codec is based on sub-band ADPCM ....
, as well as varying degrees of higher-quality audio components.
Suppliers of integrated circuits for telephony equipment, including Broadcom
Broadcom
Broadcom Corporation is a fabless semiconductor company in the wireless and broadband communication business. The company is headquartered in Irvine, California, USA. Broadcom was founded by a professor-student pair Henry Samueli and Henry T. Nicholas III from the University of California, Los...
, Infineon, and Texas Instruments
Texas Instruments
Texas Instruments Inc. , widely known as TI, is an American company based in Dallas, Texas, United States, which develops and commercializes semiconductor and computer technology...
, include wideband audio in their feature portfolios.
There are audio conferencing service providers that support wideband connections from these and other VoIP endpoints, while also permitting PSTN participants to join the conference in narrowband. sipXtapi is an open source solution for VoIP media processing engine supporting wideband and HD voice that provides RTP and codecs through a plugin framework for use with SIP and other VoIP protocols. Skype
Skype
Skype is a software application that allows users to make voice and video calls and chat over the Internet. Calls to other users within the Skype service are free, while calls to both traditional landline telephones and mobile phones can be made for a fee using a debit-based user account system...
uses an audio codec called Silk
Silk (codec)
SILK is an audio compression format and audio codec used by Skype. It is developed by Skype Limited. SILK is a replacement for the SVOPC codec.The SILK codec was a separate development branch from SVOPC and it has been under development for over 3 years....
which allows for extremely high quality audio.
A number of carriers around the world have rolled out HD voice services based on the G.722 wideband standard. In North America, hosted service providers have recently deployed the Aastra Hi-Q upgrade to its installed user base and as of January 2010 claimed around 70,000 HD voice endpoints. Consumer service provider ooma has an estimated 25,000 HD voice endpoints deployed stemming from its roll out of its second-generation Telo hardware.
After years of trials, AMR-WB was made commercially available in September 2009, when Orange
Orange Moldova
The Orange company operates in Moldova since April 1998, a 94.45% share of Orange Moldova belongs to France Télécom. The company is also an internet service provider and fixed voice services provider for business....
launched the world's first high-definition voice service for mobile phones in Moldova
Moldova
Moldova , officially the Republic of Moldova is a landlocked state in Eastern Europe, located between Romania to the West and Ukraine to the North, East and South. It declared itself an independent state with the same boundaries as the preceding Moldavian Soviet Socialist Republic in 1991, as part...
, the first time since the 1990s that mobile voice technologies have been subject to a significant evolution. The first mobile handset integrating high-definition voice capability launched by Orange Moldova
Orange Moldova
The Orange company operates in Moldova since April 1998, a 94.45% share of Orange Moldova belongs to France Télécom. The company is also an internet service provider and fixed voice services provider for business....
is the Nokia 6720
Nokia 6720
The Nokia 6720 is a mobile phone by Nokia. It was unveiled to public in Barcelona and Singapore on February 16, 2009. It comes with the latest Nokia technology such as A-GPS and active noise cancellation. The noice cancellation technology increases audibility by reducing background noise such as...
c, which integrates WB-AMR. Orange has since rolled out HD voice in the UK, France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
, Belgium
Belgium
Belgium , officially the Kingdom of Belgium, is a federal state in Western Europe. It is a founding member of the European Union and hosts the EU's headquarters, and those of several other major international organisations such as NATO.Belgium is also a member of, or affiliated to, many...
, Romania
Romania
Romania is a country located at the crossroads of Central and Southeastern Europe, on the Lower Danube, within and outside the Carpathian arch, bordering on the Black Sea...
, Armenia
Armenia
Armenia , officially the Republic of Armenia , is a landlocked mountainous country in the Caucasus region of Eurasia...
, Dominican Republic
Dominican Republic
The Dominican Republic is a nation on the island of La Hispaniola, part of the Greater Antilles archipelago in the Caribbean region. The western third of the island is occupied by the nation of Haiti, making Hispaniola one of two Caribbean islands that are shared by two countries...
and Catalonia
Catalonia
Catalonia is an autonomous community in northeastern Spain, with the official status of a "nationality" of Spain. Catalonia comprises four provinces: Barcelona, Girona, Lleida, and Tarragona. Its capital and largest city is Barcelona. Catalonia covers an area of 32,114 km² and has an...
, with Switzerland
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....
and Luxembourg
Luxembourg
Luxembourg , officially the Grand Duchy of Luxembourg , is a landlocked country in western Europe, bordered by Belgium, France, and Germany. It has two principal regions: the Oesling in the North as part of the Ardennes massif, and the Gutland in the south...
due to follow.
Three UK launched HD voice calls onto their network at the end of May 2011.
External links
- www.hdvoicenews.com – HD Voice News
- The Effect of Bandwidth on Speech Intelligibility – Polycom technical White Paper
- TMCNet.com HD Voice Community
- VoIP transitioning to High Definition Voice – InfoWorld blog on wideband audio
- Texas Instruments HD Audio website
- Can You Hear What I Mean? Polycom Delivers HD Voice – sponsored IDC White Paper
- International Telecommunications Union
- HD VoIP Sounds Better – AudioCodes White Paper
- HD Voice Cookbook