HD Voice: The Future Is Clear

It’s ironic in a way. LTE breakthroughs, sensational applications … we’re in an industry that is always trying to deliver the next “new thing.” Yet, one thing remains unchanged: Nothing will ever replace the sound of a voice, that is, unless the voice sounds better. And as I watch people experience high-definition (HD) voice for the first time, it’s clear that this will be the future standard: No one want will want anything less.

I recently provided a demonstration of HD voice during a “Lunch & Learn” to a group of about 40 iBasis employees gathered in a large cafeteria-style room. I had two colleagues dial in to a conventional audio conferencing bridge while I dialed in via one of those star-shaped Polycom conference phones. After the usual frustrations of effectively cancelling each other out by talking simultaneously and sounding rather distant and “muddy,” we ended the call, mercifully. Turning to face the other Polycom phone (the IP conference phone), I said, “Mauro, are you there?” and when my colleague in Brazil responded, “Yes, I’m here” the audience in the room gasped and mouths dropped open. 

It sounded like Mauro was literally in the room. Heads turned half expecting to see him standing in the doorway. Then Manpreet, who had been on the conventional bridge call, dialed into the HD bridge and the two of them started talking over each other.  While it didn’t make for good conversation, everyone in the room heard every detail with great clarity. Likewise, they were able to hear every comment and question from the audience. If you’ve ever tried to use a basic conference phone in an oversized room, without satellite microphones, you know how atypical this experience was.

The narrowband voice of public switched telephone network circuits operates between 300 Hz to 3.4 Khz. On the other hand, HD, or wideband, voice transmits a much wider spectrum, from 30 Hz to 7Khz. The consonants f, s, m and n, collectively known as fricatives, are difficult to understand via narrowband but easy to distinguish with HD voice. The same is true for foreign accents and conversation that has to compete with background noise. HD voice offers double the voice quality for typical mobile calls versus mobile narrowband. And, this greatly improved quality is accomplished without increasing capacity.

The reaction of my internal “Lunch & Learn” audience represents a very great market opportunity operators have with HD voice. When someone calls from half-a-world away and sounds as if they’re in the same room, it makes a huge difference. As a result, callers stay connected longer, and that translates, in any language, into increased revenue and reduced churn. Proof of this is Skype’s use of the SILK HD codec, which resulted in a 50 percent increase in call duration. Additionally, in an Ericsson and T-Mobile consumer trial conducted in 2006 -- based on 150 users with mobile HD phones -- 70 percent reported a distinct improvement in voice quality. Particularly noted was their improved sense of privacy, discretion and comfort, and the technology’s enhanced performance in noisy environments. 

On the business-customer side, the same benefits apply. Furthermore, if you’re an enterprise operating a call center, HD voice quality results in more effective communication. That translates into higher customer satisfaction because call center reps can resolve issues faster, which also means better cost-efficiency because a greater amount of enquiries can be handled in less time.

The applications of HD voice are also considerable: audio conferencing, interactive voice response and voice mail, ring-back tones, point-to-point HD voice domestically and internationally, video telepresence -- the list goes on. HD voice offers a chance to increase revenue for both fixed and mobile operators, and, to gain a competitive advantage that can result in increased market share and brand loyalty.

HD voice is just one more reason for operators to expedite their migration to and use of IP networks. End-points require IP for HD voice connection, without transcoding standing in the way. Currently, several mobile networks offer transcoder-free service, though there might be some licensing costs involved. For consumers and businesses, many mobile handset manufacturers already offer HD-ready products. For network operators, standardizing on HD voice codecs is a key focus area for the i3 Forum  and the GSMA’s IPX working group. iBasis is an active participant in both.

If you’re interested in hearing online audio samples of HD voice, VoiceAge, a company that develops speech and audio compression technologies, offers comparisons of narrowband versus wideband sound.

Ajay Joseph is CTO of iBasis, where he is responsible for the technical strategy, innovation and engineering of the company’s global telecommunications network and supporting systems.