I’ve long had a fascination with spatial audio processing. This was in part why Voxeet caught my attention when the service initially launched. It was over a year before we were able to have them appear on VUC #471 on January 10th.
From that session you may recall that Voxeet offers a binaural conference service. Participants join a conference using a PC smart phone application. They use a stereo headset allowing the client application to provide placement of the individual participants within a controlled sound stage.
Voxeet is interesting. However, it’s not exactly clear what aspect of the service is most compelling. At point of launch they used the Speex audio codec, which allows wideband audio (aka HDVoice.)
In the recent v2 release their PC client has been moved to a WebRTC foundation, leveraging Opus. I’ve done a quick analysis of their updated online demo. Newly fitted with American voices where there were once French accents, it presents 16 KHz usable audio path, suggesting a 32 KHz sample rate. It certainly sounds very good.
Sometimes people take the shortest or cheapest path when it really doesn’t serve them well. So it was for my employer. For the past year or more the IVR menu at our main US number was voiced by the CEO of our US operation. Not that his voice is bad, but he’s an ex-pat Englishman with an accent that emphasizes the fact that we’re not a US-based company.
A while ago bkw of Freeswitch fame tweeted something about using Fiverr.com to find Lauri Murdock to voice some IVR. Fiverr.com is a site where people offer whatever service they provide for $5.
Since we had recently made some changes in staffing we needed to rework our IVR tree. I thought, hey for $5 noone is going to complain if we get a nice female voice. So I just ordered recording without asking anyone about it.
Phil Campbell caught up with Jeff Pulver at SXSW last month for a nice little interview. Jeff passed on some thoughts about SXSW and social media. He describes some of his impression of the importance of wideband voice, and the HD Communications Summit that he’s planning in May.
The VoIP Users Conference weekly call on Friday, November 7, 2008 is all about wideband telephony. That is, using VoIP to deliver call quality vastly superior to the normal public telephone network (PSTN.) Our guest will be David Frankel, CEO of ZipDX, a commercial conferencing service that is specializing in wideband conference calling for businesses.
As usual anyone may join the call which gets underway at 12 noon EST on the Talkshoe conference service. That conference service can be reached by dial-in over the PSTN or by SIP URI. Details on how to connect to Talkshoe by various means can be found here.
For this one call only we will also be using the ZipDX wideband conference bridge. ZipDX and Talkshoe will be connected so that everyone will be on the call. Anyone connected to the ZipDX bridge using a suitable phone will be able to experience the call in G.722-based wideband quality.
Everyone else will experience the normal G.711 based narrowband conference quality that we all know and (despise) love.
As I prepared for my travels this week I stuffed a bunch of papers into my bag not really noticing what was in the stack. As I am presently on an airplane en route from San Francisco to Seattle I had an opportunity to review what I’d brought and came upon a white paper from Polycom Co-Founder & CTO Jeff Rodman entitled “VoIP to 20 kHz: Codec Choices for High Definition Voice Telephony.”
This paper which was released in July 2008 is freely available on their web site and is an excellent overview of the state of the codec world and the potential for better-than-PSTN-quality IP telephony. It takes a well balanced view of existing codecs, their ability to convey audio bandwidth, latencies, target applications, network bandwidth and processor load requirements. It gives a significant amount of detail while presenting the information in language that even a non-technical manager will appreciate.
If you have any interest in the future of IP telephony it’s definitely worth a read.
For the past few weeks I’ve been hunting for a soft phone with specific wideband voice capabilities. I’ve found a couple but there arises complications.
Wideband-capable hard phones usually support G.722, G.722.1 or G.722.2 (aka AMR-WB) codecs. There are other codecs out there that support wideband voice coding. Speex is the one most often cited. However, Speex support in hardware is extremely limited. So Speex implemented in a soft phone is not going to help me evaluate interoperability with hard phones.