This is an unabridged version of a (shorter) presentation I gave at last month’s ICOHTEC meeting in Porto (see session T1E in the conference programme). I would like to thank my fellow panelists, Susan Schmidt Horning, Melissa Van Drie and Krin Gabbard, as well as the session chair, Hans-Joachim Braun, and the audience for helpful comments and questions.
The design of a dummy head, or Kunstkopf, microphone is rather simple: it replicates an average sized human head that is equipped with pinnae and ear canals in which small microphones are placed, one in each ear. During the 1930s, first dummy head experiments were conducted at Bell Telephone Laboratories in Murray Hill, New Jersey, and the Philips Research Laboratory in Eindhoven, the Netherlands.Bell engineers Steinberg and Snow summarized that dummy head sound transmission aims “to reproduce in a distant listener’s ears, by means of [headphones], exact copies of the sound vibrations that would exist in his ears if he were listening directly”. Head-related stereophony, or binaural sound reproduction, enabled the listener to experience the spaciousness and presence of the original recording situation, thus it seemed to fulfill the listeners’ desire for “concert hall realism”. However, because of technically limited recording equipment and insufficient understanding of human spatial hearing, it took more than 30 years before dummy head microphones got ready for the market with the KU80 dummy head. In late 1972, the Berlin based microphone company Neumann, shipped first KU80 models to customers in Germany, Austria and Belgium. The following year, the general public was introduced to head-related stereophony during the International Broadcasting Fair (IFA) in Berlin. Trade fair visitors could listen to test recordings at the stand of the joint organization of Germany’s regional public-service broadcasters (ARD), and the Berlin radio station RIAS broadcasted the first binaural radio drama: “Demolition”. Journalists praised head-related stereophony as “super stereo” and radio listeners wrote enthusiastic letters asking for more binaural broadcasts. Sound professionals were much less enthusiastic: they admitted the spatial quality of the recordings, but because of some technical shortcomings of the KU80, most sound recordists rejected binaural sound recording. The following ten years were full of high hopes and many disappointments and by the mid-1980s dummy head microphones were regarded as a largely failed technology.
In the following, I will briefly describe the “audio-technical discourse” that accompanied the introduction of head-related stereophony. Examining the “auditory perspective” of recordists and sound technicians, I will argue that the failure of dummy head microphones was less grounded in technical problems but in recording practices, listening modes and aesthetic concepts of the time. I will further show that the way sound professionals “audiopositioned” ordinary radio listeners was in contradiction with the listeners own experience and demands.
Radio drama played a crucial role in dummy head history but today I will focus on music recordings. Furthermore, my geographical focus will be on Germany, in particular on the two West-Berlin radio stations RIAS (Radio in the American Sector) and SFB (Radio Free Berlin). Broadcasters in other European countries and Canada also showed interest in head-related stereophony, but RIAS and SFB extensively used dummy head microphones between 1973 and the early 1980s. SFB pioneered binaural music recording; RIAS was more specialized in binaural radio drama, but RIAS editor Ulrich Gerhardt, one of the most important advocates of head-related stereophony, also presented binaural music recordings in his biweekly program “Kunstkopf-Studio”.
1973-1983: The decade of head-related stereophony, or: ten years of high hopes and many disappointments
During the ten days of the 1973 International Broadcasting Fair (Aug. 31–Sept. 9, 1973), about 2.000 visitors of the ARD glass studio listened to a 26 minutes demonstration tape with different binaural recordings. Approximately 40% of the listeners were sound professionals from broadcasters, recording studios and trade journals. On September 3, 1973, RIAS broadcasted the first binaural radio drama “Demolition”. The two co-producing stations, Bavarian Broadcast (BR) and West-German Broadcast Cologne (WDR), aired “Demolition” a few days later. The three broadcasters received roughly 2.000 enthusiastic letters and postcards, and RIAS another 1.000 telephone calls. The daily press was also full of praise for the new “super stereo” technology. And two years later, at the 1975 IFA, the ARD dummy head studio counted some 100.000 listeners.
Animated by the great success of “Demolition”, the two Berlin broadcasters RIAS and SFB decided to produce more binaural recordings and to experiment with different formats and recording situations. It was agreed that RIAS would focus on radio drama and feature, and SFB on musical recordings, in particular, of classical music. The recording of symphonic music had been the original aim of the dummy head inventors. In 1969, Georg Plenge, Ralf Kürer and Henning Wilkens from the Technical University of Berlin started to investigate room acoustics of concert halls. For more objective listening tests, they came up with the idea to use a dummy head microphone to record a musical performance and to play back the binaural recording to their test persons thus enabling a number of listeners to hear the exact same performance from the same seat in the house.
The music department at SFB worked intensively with Neumann’s KU80 throughout the year 1974, and established itself as center of dummy head “research” that received many visitors from foreign radio stations. In July 1974, SFB broadcasted the first binaural recording of a symphonic concert. The program director later reported that “telephonic and written reactions of listeners have been unusually positive.” SFB simultaneously broadcasted a number of stereo and Kunstkopf recordings of different orchestra formations and room acoustics, so that listeners could directly compare both technologies when switching between the two FM channels.
In his letter, one exemplary listener admired the “perfect, natural and spatial sound” of the binaural recordings. He was happy that dummy head recording had left the experimental phase to now broadcast concert-length performances. “I am really impressed by these first proper music recordings” he noted, in particular he liked the live broadcast of Bach’s “Kunst der Fuge”, and of a poly-choral performance. This listener experienced a complexity of sound he had never heard before on radio; he even enjoyed a binaural rock concert although he usually disliked this type of music.
The first experimental phase ended in September 1974, and the SFB music department asked for extra money (50.000 DM) to continue with binaural recordings. The money was granted and used for first experiments with popular dance music. Wilhelm Schlemm, one of the few recordists who actively promoted dummy head technology, was assigned to record the SFB dance orchestra at the Berlin Hansa-Studio which was equipped with the latest multi-track equipment. During the recording session, Schlemm discovered that the studio sound was not interesting enough for a binaural recording. Hence, he decided to record only the rhythm sections in the studio, and the melody sections in the Grunewald church in Wilmersdorf – well-known for good room acoustics. Schlemm proved that binaural multi-track recording was possible: a “step forward for dummy head recording”, he reported. The recording was also presented at a meeting of the European Broadcasting Union (EBU) and the conference report noted that “a number of delegates found this a very convincing recording and felt that the chorus and wind instruments were clearly distinguishable outside the hearer’s head.”
Despite the efforts of Schlemm and his colleagues, and despite the very encouraging feed-back from (radio) listeners, binaural music recording did not really leave the experimental stadium. In 1978, the RIAS music department admitted that they could not start a regular four-weekly 30 minutes broadcast because of a lack of available binaural recordings. After ten years of extensive binaural experiments, most commentators agreed that dummy head technology, in general, and binaural music recording, in particular, had failed.
“Technical” problems, or: the experimental stadium of dummy head recording
As described before, only few broadcasters (and recording studios) experimented with head-related stereophony. One reason was that most recordists, sound engineers and technicians refused to work with dummy head microphones. The three inventors had already presented their dummy head at the 1969 (Tonmeister) meeting of German recordists, but they found nobody willing to start recording with it. It was left to the RIAS radio drama department to adopt the technology four years later.
The great success of “Demolition” and subsequent binaural broadcasts provoked a response by the sound recording community. In the related discourse about head-related stereophony, most trade journalists and sound professionals admitted that binaural recordings provided good localization of direction and distance, realistic room acoustic, and immersed listeners into the recording situation. However, recordists immediately questioned the technology’s readiness for use because of a number of technical shortcomings. One such problem that was prominently discussed was missing front localization. Many listeners could not locate sound sources in front of them. For example, in a study of the research institute of German broadcasters (IRT) 85% of 160 test persons located the orchestra behind them. This was seen as a principal design problem: one explanation was that the human brain refuses to locate sound sources in the front if there’s no corresponding visual stimulus. Binaural advocates responded that one needs to learn binaural listening and that future dummy head models would probably allow better frontal localization.
A second problem that was often discussed was a loss of high frequencies. Initially this was also seen as a principal shortcoming of binaural sound reproduction, but later it turned out to be a specific problem of the KU80 model. In a discussion at the 1976 Tonmeister meeting, Henning Wilkens, one of the inventors, also voiced his surprise that sound engineers did not use the available technical means to correct the dummy head’s frequency response by simply amplifying frequencies around 5,6 kHz.
As a third problem technical compatibility was discussed. In fact, compatibility could mean three different things: broadcasting compatibility, mono/stereo compatibility, and loudspeaker compatibility. First, head-related stereophony was, like conventional stereophony, only compatible with FM broadcasting. Most German broadcasters had introduced FM stereo broadcasting during the 1960s, but some still offered AM broadcasts. Second, mono reproduction of binaural signals resulted in unpleasant coloration. This was problematic because 80% of German radio listeners still used mono receivers. Third, binaural recordings could not be reproduced with loudspeakers. When listening with loudspeakers no sound localization was possible, and, furthermore, the tone quality was distorted. Thus, head-related stereophony could only be enjoyed when listening with headphones, and this dependence was criticized by sound professionals. For one, they argued that most users did not want to listen attentively, the apparent “natural” mode of listening with headphones. Ulrich Gerhardt replied that formats like radio drama, symphonic music, chamber music or operas could always count on the listeners undivided attention, so the use of headphones posed no real imposition. At the 1972 Tonmeister meeting, Klaus Bertram, from Radio Bremen, added that headphones did not only ask for attentive listening, but they were simply less comfortable. However, Bertram’s intervention also shows that the audio-technical discourse about dummy head technology was not only a technical discourse, because he continued his critique that head-related technology also offered recordists less manipulability.
“Aesthetic” problems, or: the (artistic) position of German recordists
Bertram’s last argument shifted the discussion from technical to aesthetic aspects of head-related stereophony and the latter also touched upon the professional identity of German recordists. “Tonmeister” was a new artistic-technical profession which was founded in 1949 through a new study program of the music academy in Detmold. Here, recordists received musical and technical training to become mediators between the artistic and technical spheres of music recording. The Tonmeister program helped to establish a community of practice with distinct listening practices and an aesthetic ideal which turned out to be incommensurable with dummy head’s true-to-original sound transmission.
In his talk “The transmission of the natural sound pattern”, Nikolaus Schampaul, recordist of West German Broadcasting Cologne, elaborated, in 1969, that the transmission of the natural sound pattern did not mean true-to-original sound transmission, for example with a single microphone placed at the best seat in the house. Instead, for him, the transmission of the natural sound pattern relied on subtle technical manipulations. Schampaul stated that in recording practice the ideal of “concert hall realism” could only be achieved through aesthetic choices of the recordist. In another talk, musicologist Hans-Peter Reinecke, provided a physiological (or better: neurological) justification for the recordists’ intervention: He explained that the lack of visual stimuli demanded the alteration of acoustic information to achieve a close to “original” listening experience.
Hans-Ludwig Feldgen, director of the Tonmeister program at the Berlin music academy, declared that recording practices were constrained by the “autonomy” of electro-acoustical technologies. Feldgen argued that each electro-acoustical systems had different (technical) affordances, and each demanded therefore a specific technique of musical communication. This is why musicians initially had to learn that their demand for a true-to-original sound transmission was not ideal for technical mediated music reception. Au contraire, Feldgen emphasized that a naturally sounding reproduction was usually the result of intensive technical processing.
The “nature” of dummy head recording seemed to be the “undesired” documentation of sound events in the original sense of true-to-original reproduction. Thus dummy head technology appeared to be incongruent with dominant electro-acoustical aesthetics. In a presentation at the 1976 Prix Italia festival, dummy head advocate Wilhelm Schlemm also admitted that the documentary style of binaural recordings he experimented with in the first phase was, in the end, not pleasing. He still saw great potential for dummy head recordings in capturing the performance of particular spatial compositions typical for music of the 16th to 18th century and contemporary avant-garde music.
However, critics, like Ernst Rothe, EMI chief recordist, emphasized that “the sound, the dummy head records, is not what listeners want to hear these days.” Hans-Ludwig Feldgen countered such apodictic arguments with the listeners’ positive responses. Self-critically, he added, that recordists had maybe gone to far and that binaural technology could help to correct our aesthetic concepts. In the same line of argumentation, Wolfgang Geiseler, head of the RIAS music department, asked in a presentation at the International Rostrum of Composers in Paris whether the latest development in electro-acoustical technology was going into the right direction. Maybe it would be better to force “the technology to record more or less like humans hear.” He then presented different dummy head recordings, e.g. a binaural recording of Herbert von Karajan in the Berlin philharmonic hall. Geiseler acknowledged that these recordings sounded completely different than common “over-developed” stereo recordings. In the end, Schlemm, Feldgen and Geiseler could not convince their fellow recordists and dummy head stereo became a marginalized technology – with a second, more successful life in technical acoustics.
To conclude, dummy head technology seemed to have a promising future when it was presented to the broad public at the IFA 1973. If electro-acoustic sound reproduction was a matter of “fidelity”, the choice would have been head-related stereophony. However, recordists and other sound professionals first ignored and then boycotted binaural recording at large, and after a decade of high hopes and many disappointments dummy head technology turned out to be a failed innovation.
The “standard” narrative lists a number of technical problems to explain this failure: e.g. location problems, like missing frontal localization or inversion of direction; problems with reproduction of high frequencies; high inherent noise level; or unpleasant coloration when listening with loudspeakers. Dummy head critics also argued that radio listeners were unwilling to wear headphones, thereby disregarding the unusual high and mostly positive feedback from listerners.
Ulrich Gerhardt presented an alternative narrative and accused recordists of dismissing dummy head technology out of conservative attitudes and a reluctance to make experiments. This is at least not the full story because the sound recording business experienced massive technical changes throughout the 1960s and 70s, and inventions like tape or multi-track recording were quickly adopted into the daily recording practice.
However, what these excepted technologies had in common was that they extended the recordists’ audio-technical scope of influence. By contrast, dummy head microphones seemed to limit the recordists audio-technical possibilities, and they “feared to loose their artistic role of musical-aesthetic microphoning”. This rather aesthetic than technical conflict helps to explain the “ideological furor” with which recordists argued in favor or against head-related stereophony. At the heart of the audio-technical discourse about dummy head technology was what Susan Schmidt Horning has termed the recordists’ “aural thinking”. Since the beginning of electro-acoustical recording, recordists were oriented towards recording and reproducing individual sound sources (e.g. through close microphoning); technologies like Kunstkopf stereophony are instead oriented towards the listeners point of audition and require a completely different “auditory perspective”, i.e. another mode of sound reproduction (Ersatz sound source instead of phantom sound source) and an alternative mode of listening (on the side of the recordists, and on the side of the radio listener).
A brief note on sources
I have presented this paper at the ICOHTEC meeting 2016 in Porto during the session “Innovations and Mediations in the Technologies of Sound and Image: 1890s-1990s”, which I organized together with Susan Schmidt Horning. It is primarily based on a close reading of archival sources from the Broadcasting Archive in Babelsberg (Deutsches Rundfunkarchiv), in particular documents from SFB and RIAS, and the archive of Bavarian Broadcasting (Archiv des BR), as well as papers from Tonmeister meetings (all published in the Tonmeister proceedings). I hope to (soon) publish an extended version of the paper (with detailed references) in an academic journal.