Issue link: https://digital.copcomm.com/i/1490686
52 I M PS E . O R G "Sound is the skin of the film in that it actually engages the audience's vibrotactile receptors." Uruguayans often use the word feel when referring to sound. For instance, my sister in law often says "It felt loud" or "I felt it" instead of "It sounded loud" or "I heard it." Bruce R. Smith says in 'Hearing History; A reader.'; "Sound provides the most forceful stimulus that human beings experience, and the most evanescent." (Bruce R. Smith, 2004). The reason sound and touch are so intimately related, at least in the West, is that their mechanical frequency range overlap. Thomas Lund claims that this happens at around 50 Hertz (Lund, 2020), while more recent research by Merchel and Altinsoy suggests the overlap between them is larger, between a few Hertz and several hundred Hertz and that our vibrotactile sense goes up to approximately 1 kHz. We sense vibration not only with our ears but with other parts of the body like our skin and our abdomen. When sound waves travel through the air and when they arrive at our bodies, we sense them both with our ears and with our bodies' mechanoreceptive system. "Mechanoreceptors detect stimuli such as touch, pressure, vibration, and sound from the external and internal environments." (French and Torkkeli, 2009). We hear vibration, that is, we sense it with our hearing system, when sound waves or vibrations have frequencies within 20 Hz and 20 kHz. And we also feel vibration with our body. Specially low frequencies; "Of all frequency bands within a sonic encounter, bass most explicitly exceeds mere audition and activates the sonic conjunction with amodal perception: bass is not just heard but felt." (Goodman, 2012). This means that our bodies can feel vibrations that go up to approximately 1 kHz, "Only frequencies up to approximately 1 kHz can be perceived via the mechanoreceptive system." (Merchel and Altinsoy, 2020). On the lower end, we can feel vibrations as low as 1 Hz, while our bodies are most sensitive to vibrations between 4 Hz and 8 Hz, "Humans are most sensitive to vibration frequencies in the range of 4–8 Hz, due to resonance within the body cavity itself" (Grether, 1971). In modern cinemas the lower limit is 25 Hz on a Dolby Atmos compliant subwoofer for example. "The Low- Frequency Effects channel subwoofer must have a flat response over the range of 25 Hz to 120 Hz and a minimum output capability of 115dB continuous Sound Pressure Level (SPL) at the Reference Listening Position (RLP)." (Dolby Laboratories, 2015) The reason they require a minimum output capability of 115dB is because in order to be felt, low frequencies need to be several times more powerful than the frequencies we use for speech. This means modern subwoofers are able to produce sound waves with a wavelength of 9 to 13 meters long and with a SPL well over 100dB. That is enough vibration to make our popcorn and our whole seat shake. In film post-production and music production low frequencies are boosted to counteract this limitation, or rather, this natural design, and thus can be heard at the same apparent loudness as other frequencies. On account of this and the rapid improvement in loudspeaker potency, frequency response and clarity, modern cinema sound, just as modern music is rich on low and low-mid frequencies and can be a very nuanced medium to render texture, size and shape through sound. Film being an audiovisual medium, entails it also shares the physical properties of sound when it is played through any speaker; it has a temporal dimension, as well as a spatial dimension. Sound needs a medium, such as air or water through which to propagate, whereas electromagnetic waves which include the visible light, have little difficulty in radiating through the vacuum of space. If we try watching a film with the sound muted, we'll immediately notice what George Lucas is talking about when he says, "Sound is half the experience…" Because it is missing its spatial, mechanical and tactile dimensions. It feels rather flat or neutral to our bodies in that it lacks sonic contour and texture. Having the cultural expectation of movies being audiovisual adds to the feeling that when we're experiencing one without sound, we're experiencing it only partially. If we watch the film muted with subtitles we could maybe follow the story along, but let's not fool ourselves thinking we're experiencing a film when in reality what we're doing is more akin to reading illustrated literature. If we try listening to a film with our eyes closed, it will be an experience more akin to radio. The cinematic experience really demands the undivided involvement of both vision and hearing. Sound is the skin of the film in that it actually engages the audience's vibrotactile receptors; "In the overlapping frequency range of auditory and vibrotactile perception, vibrations are likely to stimulate mainly the Meissner and Pacinian mechanoreceptors which can be found all over the body." (Merchel and Altinsoy, 2020).