Alan Blumlein recordings

Long description:

Selected recordings can be played by anyone.

These recordings, made by Alan Blumlein, represent some of the earliest experiments in two-channel sound recording.

Alan Dower Blumlein (1903-1942) was a prolific inventor and innovator of technology. He had a penchant for problem solving that allowed him to move from research project to research project with equal brilliance; thus he was a highly valued asset at the International Western Electric Corporation, Standard Telephones and Cables, the Columbia Graphophone Company, and Electric and Musical Industries (EMI). Blumlein is recognized for his contributions to telegraphy, sound recording and reproduction, television, radar, electronic engineering and circuit design. Blumlein was granted 128 patents between the years of 1928 and 1945. During WWII, Blumlein lent his expertise to the development of sound locators and radar, both of which aided British armed forces in countering enemy attacks.  While conducting in-flight radar tests onboard a Halifax bomber, an engine fire caused the aircraft to crash, killing all passengers. June 7, 2012 marked the 70th anniversary of Blumlein’s tragic passing.

These 22 sound recordings (9TS0003378-9TS0003399) were digitally transferred from single-sided, binaural test records created by Alan Blumlein and his research team at EMI. They were thoughtfully donated to the British Library in 2005 by the family of the late Angus McKenzie. They represent some of the earliest known experiments in two-channel sound recording. Included in this collection are several recorded speech trials featuring Blumlein and members of his research team walking and talking in the auditorium of the Hayes research building in 1933, as well as several recorded fragments of a rehearsal performance of Mozart’s Jupiter Symphony conducted by Sir Thomas Beecham and performed by the London Philharmonic Orchestra at Abbey Road Studios in 1934.

Blumlein had theorized several binaural (two-channel) recording methods as early as 1931, but could not pursue their realization in the laboratory until EMI was convinced that allocating resources to the development of such a system would be fruitful. In 1932, Blumlein carefully crafted a memo to Isaac Shoenberg, the Director of Research and Development at EMI, explaining, in layman’s terms, the benefits of a two-channel recording system in contrast to the single-channel, monophonic recording system which was then used in both gramophone recordings and film soundtracks. Shoenberg became intrigued and allowed Blumlein’s team to begin developing the binaural recording system. According to Blumlein’s memo, the primary benefit of a two-channel recording was the listener’s ability to clearly distinguish sound sources from one another as well as from reverberant echoes characteristic of the room in which the recording was made. Of secondary importance, was the added benefit of hearing sounds spread between left and right loudspeakers. Interestingly, it is this left-right information we now value most about stereo recordings.

Blumlein’s methods were unique. While his contemporaries at other research laboratories found great difficulty in reproducing the spatial location of low-frequency sounds over loudspeakers, Blumlein devised a specialized circuit called a “shuffling network” that allowed all sounds to be more accurately located by listeners in the space between loudspeakers. The recordings in this collection are tests of Blumlein’s shuffling circuit.

As the shuffling circuit is engaged and disengaged throughout the recordings, one can easily discern the added clarity of the two-channel mode over the single-channel mode; multiple voices and footsteps can be heard as distinct sound sources, and the echoes of the auditorium in which the recordings were made do not detract from sounds in the foreground. Participating in these tests were Alan Blumlein, Alfred Westlake, Felix Trott, Maurice Harker and Ivan Turnbull, all of whom can be heard walking and talking.

Kelly Caringer (Edison Fellow 2011)