Pricing

The V Maze is a behavioral apparatus used to assess acoustic preferences in monkeys. Like humans, non-human animals find some sounds pleasing when compared to other sounds like monkey’s McDermott & Hauser, 2004), parrots (Patel et al., 2009), sea lion (Rouse, Cook & Large, 2016), bonobos (Large & Gray, 2016), and chimpanzees (Hattori, Tomonaga & Matsuzawa, 2016). However, acoustic preference may differ between humans and non-human primates (McDermott & Hauser, 2007). The preference for a sound in primates depends on the sound’s intensity and amplitude, behavioral relevance, consonance, and tempo (McDermott & Hauser, 2007; McDermott & Hauser, 2004). The V Maze measures the sound preference of acoustic music by evaluating these variables. 

The V Maze is a behavioral apparatus designed for monkeys to assess acoustic preference. It consists of a V-shaped apparatus with two arms providing two choices for the subject. The subject chooses to enter one of the arms based on its preference towards the sound generated at each arm’s end. The V Maze can also be utilized for other non-human primates such as chimpanzees. 

Other apparatuses to measure sound preference in other animals includes the Acoustic Startle Chamber and the Sound Attenuating Chamber. 

The V Maze is composed of an elevated V-shaped apparatus with two arms. Each arm end is provided with a speaker, which is concealed with black cloth. Each arm’s frame is made of acrylic, and the walls are made of wire mesh. The maze entrance is provided with an acrylic door attached with a rope connected to a pulley system so that it can be opened in the researcher’s absence. There is a sound meter attached at the center point of the maze where the two arms intersect.

Thoroughly clean the apparatus before each trial to avoid the influence of residual stimuli. Properly lit the apparatus. An external tracking and recording system such as Noldus Ethovision XT can be used with recordings and observations. 

The V Maze Acoustic Preference Task

Move the subject from the home cage to the test room. Place it near the entrance of the V Maze. Leave the room and allow the subject to enter the maze by opening the door through a pulley system. Start the playback of the arm where the subject enters first. Keep on playing it till it moves to the other arm, then start the playback sound for this arm. After 5 minutes, remove the subject from the maze and move it to its home cage.  Conduct one trial per day for 2 consecutive days. Now switch the sounds and conduct one trial per day for 2 consecutive days. 

Investigation of acoustic preference in tamarins

McDermotta & Marc Hauserb  (2004) evaluated the sound preferences in cotton-top tamarins. Four experiments were performed using the V Maze. In experiment 1, subjects were exposed to loud and soft voices to assess preference based on sound intensity. In experiment 2, subjects were exposed to feeding chirps and distress calls to assess distress calls’ preference. In experiment 3, subjects (n=6) were exposed to consonance and dissonant sounds. In experiment 4, subjects were exposed to screeching sounds. The sound preference for experiments 3 and 4 was also assessed through humans. The results of experiment 1 revealed that tamarins showed preference and spent more time (70%) on the side with soft noise (t(23)5.5, p>0.00001). Tamarins (n=5) spent more time on the side playing species-specific feeding chirps than on the side playing species-specific distress calls in experiment 2 (t[40]2.53; p<0.01). In experiment 3, tamarins (n=5) showed no preference to consonant versus dissonant sounds (t(30)0.47;p<0.32). While humans (n=4) spent more time in consonance side (t[3]10.26;p<0.001)  Lastly, tamarins (n=5) showed no preference to screeching sound compared to white noise (t(36)0.89; p<0.15). The study concluded that sound preferences in primates differ from human preferences. 

Investigation of music preference in tamarin, marmoset, and humans

McDermotta & Marc Hauserb  (2007) evaluated the music preferences in cotton-top tamarins, Mermosat and humans. Four experiments were performed using the V Maze. In Experiment 1, Tamarins (n=4) and Mermosat(n=4)  were exposed to two contrasting lullabies, such as a Russian lullaby played on a Xute and an excerpt of German electronic techno. In Experiment 2, Tamarins (n=4) and Mermosat (n=5)  were exposed to the same lullabies but with click trains; 40 clicks per minute, and 400 clicks second the other side. In experiment 3,  subjects were presented with the same stimuli with a choice between a pure tone with either a square wave or a triangle wave amplitude envelope. In Experiment 4, human adults (n=8), tamarins (n=5), and marmosets (n=5) were presented with noise and silence, and their preferences were evaluated. In experiment 5, subjects were exposed to stimuli that varied in tempo but were equated in acoustic energy.  The results of the study showed that both tamarins (t(31)4.47, p< 0.0001) and marmosets (t(23)7.27, p< 0.00001) exhibited a preference towards lullaby over techno. In Experiment 2, both tamarins (t(31)D 3.54, p< 0.001) and marmosets (t(39)3.33, p<0.002) showed preference to 60 clicks per minute compared to 400 clicks per minute. The results of experiment 3 showed that attack velocity was not responsible for lullaby preference in experiment 1. The results of experiment 4 revealed that humans preferred music while both tamarins and marmosets preferred silence. The results of experiment 5 revealed that subjects preferred slow tempos over fast even when stimuli were equated for acoustic energy. The study concluded that non-human primate acoustic preferences differ from humans. Unlike humans, music does not please them. However, they showed nontrivial preferences for some musical stimuli over others, depending on the tempo.

• The proportion of time spent in right choice arm
• The proportion of time spent in left choice arm

Strength

The V Maze task doesn’t require pretraining of the subjects. It imposes minimum stress on the subjects. The V maze task is easy and less time-consuming. It can be used to assess acoustic preferences in different non-human primates such as monkeys and chimpanzees. The V Maze can assess subjects’ acoustic preference for sounds with different frequencies and amplitudes, symmetry, tempo, and behavioral relevance. 

Limitations

The presence of lingering stimuli may alter observations. The species, gender, and age of the subjects may also influence task performance. The mishandling of the subject may alter observations and cause stress to the subjects. 

• The V Maze is a behavioral apparatus used to assess acoustic preferences in monkeys.
• It is composed of a V-shaped apparatus with two choice arms; each arm’s end is provided with a speaker.
• It also consists of an acrylic door at the entrance. 
• Each speaker generates a different sound, and the subject spends more time in the arm whose sound it prefers. 
• The V Maze is easy and less time-consuming. 
• The V Maze can be used to assess acoustic preference for other non-human primates such as chimpanzees, tamarins and marmosets. 

Hattori, Y., Tomonaga, M., & Matsuzawa, T. (2015). Distractor Effect of Auditory Rhythms on Self-Paced Tapping in Chimpanzees and Humans. PloS one, 10(7), e0130682. https://doi.org/10.1371/journal.pone.0130682

Large, E. W., & Gray, P. M. (2015). Spontaneous tempo and rhythmic entrainment in a bonobo (Pan paniscus). Journal of comparative psychology (Washington, D.C.: 1983), 129(4), 317–328. https://doi.org/10.1037/com0000011

McDermott, J., & Hauser, M. (2004). Are consonant intervals music to their ears? Spontaneous acoustic preferences in a non-human primate. Cognition, 94(2), B11–B21. https://doi.org/10.1016/j.cognition.2004.04.004  

McDermott, J., & Hauser, M. D. (2007). Non-human primates prefer slow tempos but dislike music overall. Cognition, 104(3), 654–668. https://doi.org/10.1016/j.cognition.2006.07.01

Patel, A. D., Iversen, J. R., Bregman, M. R., & Schulz, I. (2009). Experimental evidence for synchronization to a musical beat in a non-human animal. Current biology: CB, 19(10), 827–830. https://doi.org/10.1016/j.cub.2009.03.038

Rouse, A. A., Cook, P. F., Large, E. W., & Reichmuth, C. (2016). Beat Keeping in a Sea Lion As Coupled Oscillation: Implications for Comparative Understanding of Human Rhythm. Frontiers in neuroscience, 10, 257. https://doi.org/10.3389/fnins.2016.00257