Chapter 7.    Hearing

MAJOR EFFECTS

Acuity

The most characteristic effect of marijuana intoxication is an auditory one: "I can hear more subtle changes in sounds; e.g., the notes of music are purer and more distinct, the rhythm stands out more" (1%, 0%, 4%, 25%, 70%), which is experienced very often or usually by almost all users and occurs at a low level of intoxication (27%, 51%, 17%, 3%, 0%).
Two other items also deal with perceived auditory acuity. A very characteristic effect is "I can understand the words of songs which are not clear when straight" (4%, 10% , 20%, 29%, 37%), which also occurs at the lower levels of intoxication (19%, 45%, 25%, 5%, 1%). This is an experience clearly relevant to understanding rock music, which seems incomprehensible to many ordinary people. A rare effect on auditory acuity is "I have difficulty hearing things clearly; sounds are blurry and indistinct" (61%, 23%, 13%, 1%, 0%), a very high level effect (6%, 5%, 6%, 9%, 10%, but note that 64 percent could not rate this). The interrelationships between these three acuity effects are plotted in Figure 7-1. Hearing more subtle changes in sounds occurs more frequently than understanding the words of songs better (p <.001); and the latter effect, in turn, occurs more frequently than blurring of sounds (p <.001). Subtle changes in sounds and understanding songs have the same distribution of levels of intoxication, but the level for sound blurring is much higher than either of these phenomena (p <.001 in both cases).

Figure 7-1. EXPERIENCED AUDITORY ACUITY Note.—For guide to interpreting the "How Stoned" graph, see note on Figure 6-1.

One of the acuity phenomena is affected by background variables. Moderate Total use of marijuana is more frequently associated with understanding the words of songs better than Heavy Total use (p <.05), even though this is a very frequent phenomenon with Heavy Total users (mode at Very Often/Usually), with a suggestion (p <.10) that Light Total users also understand the words of songs better more frequently than Heavy Total users but do not differ from Moderate Total users. Users of Psychedelics also experience this more frequently than Non-users (p <.01).

Sound and Space

Another very characteristic effect also relates to the user's perception of music: "When listening to stereo music or live music, the spatial separation between the various instruments sounds greater, as if they were physically further apart" (13%, 4%, 23%, 31%, 29%), which occurs at Moderate levels of intoxication (7%, 32%, 35%, 7%, 1%). A more extreme effect on the relation of sound to space, occurring less frequently (p <.01) and at higher levels (p <.001), as shown in Figure 7-2, is "With my eyes closed and just listening to sounds, the space around me becomes an auditory space, a place where things are arranged according to their sound characteristics instead of visual, geometrical characteristics" (16%, 13%, 25%, 19%, 21% and 7%, 18%, 25%, 17%, 7%). One user offered a rich example, which happened to him when listening to stereo music on headphones: "Ordinarily I tend to hear high sounds as located further up in my head than low ones, and, with stereo, the sounds move back and forth along an axis between my ears, giving a two-dimensional display. When I'm stoned, the sounds also move back and forward in my head, depending on their quality, so I experience a beautiful three-dimensional sound space. Overtones and complex notes 'twist' the space in an indescribable way."

Figure 7-2. AUDITORY SPACE CHANCES Note.—For guide to interpreting the "How Stoned" graph, see note on Figure 6-1.

Several background factors affect the experience of auditory space. Users of Psychedelics experience auditory space somewhat more often (p <.05) than Non-users. The College-educated need to be somewhat more intoxicated than the Professionals to experience it (p <.05). The Moderate Total users need to be more intoxicated than either the Light Total users (p <.05) or the Heavy Total users (p <.05), with the Light and Heavy Total users both peaking sharply at the Fairly/Strongly level. Meditators tend to rate all intoxication levels about equally and average a lower minimal level, while ordinary Users and the Therapy and Growth group peak sharply at the Fairly/Strongly level (p <.05, overall).

Auditory Imagery

A common effect is imagery enhancement: "If I try to have an auditory image, hear something in my mind, remember a sound, it is more vivid than when straight" (16%, 7%, 26%, 27%, 20%), which occurs at Moderate levels of intoxication (9%, 33%, 27%, 7%, 3%). The Meditators and the Therapy and Growth group experience it less often than the ordinary users (p < .01, overall), as do the older users (p <.05). Further, Meditators report a somewhat higher level of intoxication for this experience than the other two groups (p <.05, overall).

Hearing Your Own Voice

One source of sound commonly heard to change by marijuana users is their own voices: "The sound quality of my own voice changes, so that I sound different to myself when I talk" (15%, 19%, 27%, 17%, 19%), mostly at the Strong level of intoxication (5%, 18%, 31%, 19%, 7%). Comments by my informants indicate that this is probably a perceptual change, not an actual change in voice quality. It occurs more frequently among the Younger group (p <.05).

Synesthesia

One of the most exotic phenomena associated with drugs is synesthesia, the experience of another sensory modality than the one actually stimulating the person. Visual sensation in conjunction with auditory stimulation is a common effect of marijuana: "Sounds have visual images or colors associated with them, synchronized with them" (20%, 23%, 33%, 16%, 7%). It occurs at high levels of intoxication (1%, 10%, 25%, 19%, 19%). Males report having to be more intoxicated to experience synesthesia than females (p <.05).

ADDITIONAL EFFECTS

A number of users offered additional effects on hearing.
Two mentioned ringing sounds: (1) "Ringing in my ears" (Sometimes, Very Strongly), and (2) "There's a loud buzz sound, like airplane motors, filling the air" (Sometimes, Maximum).
"When I listen to certain kinds of music (especially serious music) when stoned, it becomes incredibly more sensual and profound" (Sometimes, Maximum).
"When listening to music, my mind can become completely absorbed by sound to the extent that my body is writhing, but entirely disconnected from my mind" (Sometimes, Very Strongly).
"While chanting mantras, rhythmic continuity is more sensuous and secure" (no specification of frequency or level).
"Admiration for the intrinsic knowledge musicians and composers have of the effect of their sounds on people's total being" (Very Often, Fairly).

LEVELS OF INTOXICATION FOR AUDITORY PHENOMENA

Figure 7-3 orders the various auditory effects by level of intoxication. Overall differences are very significant (p<<< .0005). Experiential enhancement and enrichment of sounds appears at the very low levels of intoxication and progresses to vivid auditory images and changes in space perception in accordance with sound in the middle ranges of intoxication. Synesthesia may appear above this, and the rare effect of sounds' becoming blurry and indistinct may appear at the next-to-highest possible level.

MODULATING FACTORS

Table 7-1 summarizes those background factors that have a relatively linear effect.

Although several background factors have a relatively linear effect on the phenomenon of experiencing space as an auditory space, total marijuana use has a curvilinear effect. Moderate Total users have Very Strongly/Maximum indicated as the minimal level almost as frequently as Fairly/Strongly, while the Light and Heavy Total users peak sharply at Fairly/Strongly.
Overall, auditory effects are infrequently affected by background factors.

SUMMARY

In general we may note that effects on sound perception are some of the most characteristic effects of marijuana. Every effect here but one was at least common; one (subtle changes in sounds) was the most characteristic effect found in the entire study, and many others were characteristic. Further, all of these effects were perceived as emotionally pleasant or cognitively interesting, leading to greatly enhanced enjoyment of sound and music. The only exception was the blurring of sounds, which was one of the rarest effects in the study, occurring primarily at very high levels of intoxication, and was never experienced at all by most users.
The earlier discussion (Chapter 6) about perception as an active pattern-making process is applicable here, as it is to all sensory modalities. A primary experiential effect of marijuana intoxication is to make slight, ordinarily unnoticed nuances of sounds into meaningful variations. The question of whether this would produce a verifiable increase in auditory acuity by objective standards (say, in understanding the words of songs better) is quite intriguing.