We wouldn\u2019t put up with black and white television or noisy medium wave broadcasts, yet we do put up with poor audio on our telephones. We have progressed to high definition television and CD quality music transmissions, but we still walk around with cellphones and use landlines which hardly produce what could be called intelligible audio.<\/p>\n
Despite all the technological advances in the communications environment, the quality of voice communication has not improved much from the early-day carbon microphone. In fact, with the introduction of cellular services, the quality of voice has deteriorated – mainly because of the reduced bandwidth and poor quality codecs.<\/p>\n
A typical telephone voice channel is between 300 Hertz and 3,400 Hertz, with some systems only going up to 2,700 Hertz. With both the lower and higher range of audio frequency cut off, telephone speech lacks timber and clarity. One only has to listen to radio interviews carried out on a cellphone\u00a0 – even under good signal conditions the quality of speech and often suffers and becomes almost unintelligible.<\/p>\n
In a paper published in 2006 entitled \u201cThe brain model of intelligibility in Business telephony,” Jeff Rodman, the CTO of Polycom, wrote that there are five critical parameters in the physical communication of speech. They are bandwidth, reverberation, amplitude, interaction and noise. These five parameters constitute the foundation upon which speech comprehension and talker identification rests.<\/p>\n
Bandwidth is the amount of speech that is carried to the listeners. With the common restriction of 300 Hertz to 3400 Hertz, telephone systems only carriy 20% of the frequencies that are present in human speech. In contrast, some modern business audio systems such as telepresence and next generation telephones and handsets will reproduce frequencies up to 22 kHz. Perhaps more common in the next generation systems is a bandwidth of 80 \u2013 70,000 Hertz; double the audio bandwidth that most of us experience today.<\/p>\n
Christopher Geerdts, CEO of Xconnect South Africa, believes that poor voice quality is something of the past, as high definition voice (HD voice) is gaining popularity. With the wider range of frequencies, the personality of the voice tone and expression is restored, and enables easier understanding of speech. Because the HD Voice conversation is far easier on the ear, audio conferencing becomes more compelling than either business travel or meeting at video conferencing facilities.<\/p>\n
\u201cLong distance relationships become less frustrating, and spelling out words is unnecessary \u2013 no more \u2018S for Sierra, F for Foxtrot\u2019. The diverse accents of the world can become a cause for celebration and not irritation,\u201d he said.<\/p>\n
France Telecom pioneered HD Voice in 2006, and went on to gain over half a million HD subscribers, largely over their ADSL network. Riding on this success, sister company Orange has to date launched HD Voice on six mobile networks in Europe, supported by Nokia and other handset suppliers. BT has over two million enabled HD voice ports.<\/p>\n
So what stops telcos offering HD voice services? We seemingly have the broadband available so why are they so hesitant in exploiting high fidelity telephony? It is all tied up in the interconnect facilities, an issue which requires a radical make over.<\/p>\n
Why put up with crummy phone audio?<\/strong><\/a> << Comments and views<\/p>\n