Showing posts with label audio. Show all posts
Showing posts with label audio. Show all posts

Thursday, February 16, 2012

World Radio Day highlights how a technology with a long past can also have a bright future

Monday of  this week was the officially declared by UNESCO to be  World Radio day. I was listening to the latest episode of the BBC click podcast which was devoted to this event while out jogging and I was struck by how the audio broadcasting technology has both a long glorious history and a bright future.

Here are a few facts worth thinking about:
  • Radio was effectively the first world wide web. Modern radio stations tend to broadcast at frequencies that have a relatively short range so that neighbouring radio stations won't interfere with each other, but in the early days of radio stations tended to use Long Wave transmission which had a much longer range. In fact the BBC World Service has been broadcasting globally since 1932 by using a network of transmission stations strategically placed throughout the globe that would re-transmit the programs originally transmitted from London (an architecture which is strikingly similar to that of the Internet). Of course they were assisted in the early days by the existence of the British Empire, but this network is still apparently reaching and audience of almost 200 million listeners every day.
  • Radio stations were probably the first  users of social media. As soon as telephones became widespread, many radio programs adapted the phone-in model whereby listeners could phone the radio station to contribute to the discussion happening in the studio. In recent years the technology has been updated to use Twitter and similar tools, but the basic idea has been popular for many years.
  • Radio technology is cheap and truly ubiquitous. While many people listen to radio programs on very sophisticated and hence expensive devices, cheap radio receivers are affordable for even the poorest of people. In fact their power consumption is also so low that batter powered models can be used in remote areas where no mains electricity supply is available. In fact it is even feasible to have devices whose battery can be recharged by manually winding a handle.
  • Audio broadcasts can reach people even when they are busy. For example, many people listen to the radio while preparing breakfast in the morning and almost all cars come equipped with a radio that you can use to stop yourself getting bored on long journeys. I know that some people might read blogs while driving, but this is definitely not to be recommended for safety reasons. However, listening to the radio while driving is perfectly safe.
  • Modern distribution techniques like podcasting complement rather than compete with radio. I follow may different podcasts and I notice many (but not all) of the best shows are radio programs that are simply recorded and turned into a podcast with minimal effort. The skills that radio broadcasters have learned over the years enable them to produce a very high quality product and for minimal extra effort they can transform their existing radio content into podcasts that can reach a much wider audience that are outside the reach of their transmitters. In fact I know that many colleagues who are not natives of Ireland really enjoy the fact that the Internet allows them to easily keep in touch with home by listening to the local radio station from their home town.
  • Audio broadcasting is a field that is open to both professionals and amateurs at the same time. While I was in secondary school, I had great fun working as a part-time DJ on our local pirate radio station. The technology we used was amazingly cheap and low-tech even by the standards of the time. The production standards were not very high and were not really capable of competing with the real professionals, but we did nevertheless manage to build up a loyal group of listeners. It is no surprise that there never was a pirate television station in the west of Ireland despite the fact that there was a clear demand for an alternative to the single station that was available at the time - the costs of setting up even a very basic television station would be several orders of magnitude higher.
When you consider all of these factors it is clear that audio broadcasting is a technology which will flourish in the years ahead even if the tools and techniques we use to produce the program and/or listen to the content will continue to evolve.

Friday, November 25, 2011

Microphone adjustment on the Thinkpad W510

As I blogged about before, my current work laptop is a Lenovo W510 which is a really great machine once you get it working, but the setup can be a little bit tricky. Because I work on Sametime and most of my collagues are remote from me, I spend most of my days in Sametime Audio/Video meetings. When I got the laptop initially one of the factors that impressed me was the quality of the built in microphone. In fact the quality of the built in microphone was so high that I no longer had to use a dedicated headset.

Unfortunately, after a few months people began to complain that they could not  hear me clearly. Initially I was able to solve this by simply turning up the microphone gain with the "sound preferences" application, but eventually people complained that they could no longer hear me even with the gain turned up to the maximum. I was so desperate to find a solution that I even tried using Windows on my laptop, but this didn't seem to behave any differently so I was convinced that the problem was a hardware one.

I raised a ticket with our local hardware support team to see if they could repair it. They reported that when they tested it the volume coming from the microphone was OK, but there was a lot of background hiss and so they replaced the microphone control board. Initially the microphone worked OK, but then it started to tun itself off again randomly after a reboot or a suspend/resume. Now that I was convinced that it was unlikely to be a hardware problem so I did a little bit more digging on the Internet.

Eventually I found a solution. It seems that although the "sound preferences" application treats the microphone as a single device, there are actually two different devices contained within it. The alsamixer application sees these two devices as "Capture" and "Analog Mic Boost" each with their separate settings (see picture). The sensitivity of the microphone is effectively a combination of both settings, but the "sound preferences" application only adjusts the level of the "capture" device. For some reason the "Analog Mic Boost" had been turned down to 0 and when I adjusted this back up I was then able to make myself heard at team meetings.