An interesting observation of something I’ve known for some time but could not quantify so far: There is significant additional delay when I use a Bluetooth headset for a conference call compared to using the analog audio port and a wired headset. So how significant is this and how did I even notice?
Recently, I dialed into a conference call on the PC and also from my mobile phone. In other words, I could hear the downlink audio from both devices. While the mobile phone used the built-in speakers, the downlink audio was pretty much synchronized. But when I switched over to the Bluetooth headset, I noticed that the downlink audio came significantly later than on the PC. In other words, it would take me additional time to respond to something that is said compared to other people. When switching back to the smartphone speaker in the device, the downlink audio was synchronized again. I don’t have a way to accurately measure the difference, but it was in the order of a spoken word. So that’s perhaps 150-200 milliseconds? Doesn’t sound much, but anyone in the audio telephony world knows that this actually an awful lot. Not a problem for normal conference calls or one to one calls, but definitely an issue when excitement rises and several people contribute. When several people want to speak and just wait for a break to chime in, I was always late and people started to trample over each other. So for heated discussions, better used a cabled headset and you will have a head start!