Audio - a very brief history of time.

I am back to Johns Hopkins teaching this semester and really enjoying it. This semester’s class is Audio Science and Technology, one of my favorites. We review core technologies in audio from acoustics to amplification to DSP. I always start the class with a history of audio starting back in the late 1800’s. It is fascinating to me that we can, with very broad strokes, roughly break the history down into four buckets.

1880 - 1920 The mechanical age.
Recording and playback were mechanical affairs. I am sure you can picture an image of Caruso singing into a horn. The acoustic wave vibrates a diaphragm which is connected to a “stylus” which then etches the waveform onto a pliable surface. The playback process simply works in reverse.

1920 - 1980 The electronics age
High quality microphones, the refinement of vacuum tube amplification, and the development of the full range dynamic loudspeaker usher in the electronic age. Fidelity is improved, radio begins to battle home disc playback. Eventually we evolve to the stereo record, magnetic tape becomes the high performance standard. By the 1960s the transistor replaces the vacuum tube and loudspeakers become smaller because power is much cheaper. The transistor radio and cassette tape take audio portable.

1980 - 2000 The digital disc age
Nyquist gave us the promise of digital audio back the 1930’s with his now famous sampling theorem. It takes 50 years for digital audio to come to the masses. The compact disc dramatically improves fidelity at a given price and we ride the digital wave all the way to DVD, Dolby Digital, and Blu-ray. Unfortunately, the world stills does not seem ready for more than two channel high performance audio and multichannel audio dies away like the Quad records of old.

2000 - 2010 The digital download age
Around the turn of the millennium SACD and DVD audio were battling in one of our famous format wars. We all know who won: iTunes and the iPod. Over the first decade of our current century, downloaded music replaces disc based music. Fidelity is traded off for download speed and storage space.

2010 and forward The undiscovered country
In the small world of high performance audio we have finally achieved the promise of high resolution audio. Now high Res downloads are available and we are not constrained by the need for a disc format and player to reach mass market acceptance. High Res audio can be downloaded and stored on a large hard drive. The computer is now our gateway to quality audio. An explosion of USB audio DACs and the internet are now our highway to quality sound. And now “cloud computing” is poised to change audio again. We plan to upload our collections to server farms that have no livestock. In our ever connected world our music is just a wireless connection away. Pandora and similar services will help us tame the pipeline of choices.

In some ways today we are experiencing the 1920’s all over again - when the brand new format of AM radio put the mechanical home Victrola out of business because radio provided so much free content.
As in all areas of history, it seems we are going back to the future. Downloadable high res audio is a dream come true for all of us who love high performance audio. I am even crazy enough to dream that some day multi-channel high resolution audio may be at the tip of our digits.

Lastly, it is interesting to note how the pace of change has accelerated. Forty years of mechanical recording, forty years of electronic recording, twenty years of the digital disc, and now downloading seems to be giving way to streaming after just ten years. What will our audio world be like in 2015...