I understand your skepticism, but honestly, the research on this goes back to the 19th century. Grab ANY textbook on music perception. I'm looking for a chart I saw in one text that explains everything - I'll post it when I remember which book it comes from. I think it is from this one:
Jones, M. R., Fay, R. R., & Popper, A. N. (Eds.). (2010). Music perception. Springer.
FYI, we will hear a tick-tock in any pulse from 20ish-300ish bpm. Look up Justin London's work. He's got a lot of books and info on this stuff. Much of it reasonably accessible (although he still refers to tempos as the time between beats (Interonset Interval or IOI), not the number of beats per minute(BPM)) as per the standard in his field, so you'll have to bring a calculator)
Most clocks really don't make any difference, and many of the ones that do make barely any difference. And yes, I just heard a tick-tock with the online metronome, starting immediately.
Here is my bibliography for your perusing pleasure.
Selected Bibliography
Bader, R. (2013). Rhythm. In Nonlinearities and Synchronization in Musical Acoustics and Music Psychology (pp. 381-402). Springer Berlin Heidelberg.
Besson, M., Schön, D., Moreno, S., Santos, A., & Magne, C. (2007). Influence of musical expertise and musical training on pitch processing in music and language. Restorative Neurology and Neuroscience, 25(3), 399-410.
Bilhartz, T. D., Bruhn, R. A., & Olson, J. E. (1999). The effect of early music training on child cognitive development. Journal of Applied Developmental Psychology, 20(4), 615-636.
Bispham, J. (2006). Rhythm in music: What is it? Who has it? And why?. Music Perception, 24(2), 125-134.
Bolton, T. L. (1894). Rhythm. The American Journal of Psychology, 145-238.
Butler, M. J. (2006). Unlocking the groove: rhythm, meter, and musical design in electronic dance music. Indiana University Press.
Caldwell, K., Harrison, M., Adams, M., Quin, R. H., & Greeson, J. (2010). Developing mindfulness in college students through movement-based courses: effects on self-regulatory self-efficacy, mood, stress, and sleep quality. Journal of American College Health, 58(5), 433-442.
Cheek, J. M., & Smith, L. R. (1999). Music training and mathematics achievement. Adolescence, 34, 759-762.
Clayton, M., Sager, R., & Will, U. (2005). In time with the music: The concept of entrainment and its significance for ethnomusicology. In European meetings in ethnomusicology (Vol. 11, pp. 3-142).
Clynes, M. (1982). Music, mind, and brain: The neuropsychology of music (Vol. 94). Plenum Pub Corp.
DeNora, T. (2000). Music in everyday life. Cambridge University Press.
Eck, D. S. (2002). Meter through synchrony: processing rhythmical patterns with relaxation oscillators (Doctoral dissertation, Indiana University).
Franklin, M. S., Moore, K. S., Yip, C. Y., Jonides, J., Rattray, K., & Moher, J. (2008). The effects of musical training on verbal memory. Psychology of Music,36(3), 353-365.
Fujioka, T., Ross, B., Kakigi, R., Pantev, C., & Trainor, L. J. (2006). One year of musical training affects development of auditory cortical-evoked fields in young children. Brain, 129(10), 2593-2608.
Gardiner, M. F., Fox, A., Knowles, F., & Jeffrey, D. (1996). Learning improved by arts training. Nature; Nature.
Gasser, M., Eck, D., & Port, R. (1999). Meter as mechanism: A neural network model that learns metrical patterns. Connection Science, 11(2), 187-216.
Gordon, R. L., Magne, C. L., & Large, E. W. (2011). EEG Correlates of Song Prosody: a new look at the relationship between linguistic and musical rhythm. Frontiers in Psychology, 2.
Gouzouasis, P., Guhn, M., & Kishor, N. (2007). The predictive relationship between achievement and participation in music and achievement in core grade 12 academic subjects. Music Education Research, 9(1), 81-92.
Gromko, J. E. (2005). The effect of music instruction on phonemic awareness in beginning readers. Journal of Research in Music Education, 53(3), 199-209.
Haas, R. (2009). Music that works, 1-10.
Handel, S. (1993). Listening: An introduction to the perception of auditory events. The MIT Press.
Harwood, E. (1998). Music learning in context: A playground tale. Research Studies in Music Education, 11(1), 52-60.
Hetland, L. (2000). Learning to make music enhances spatial reasoning. Journal of Aesthetic Education, 34(3/4), 179-238.
Ho, Y. C., Cheung, M. C., & Chan, A. S. (2003). Music training improves verbal but not visual memory: cross-sectional and longitudinal explorations in children. Neuropsychology, 17(3), 439.
Hodges, D. A. (1996). Handbook of music psychology. San Antonio, TX: IMR press.
Hoffer, C. R. (1976). The understanding of music. Wadsworth Publishing Company.
Hoffman, R., Pelto, W., & White, J. W. (1996). Takadimi: A beat-oriented system of rhythm pedagogy. Journal of Music Theory Pedagogy, 10, 7-30.
Janata, Petr; Tomic, Stefan; Haberman, Jason. Sensorimotor Coupling in Music and the Psychology of the Groove. Journal of Experimental Psychology: General. 141(1):54-75, February 2012.
Jaques-Dalcroze, E. (1921). Rhythm, music and education. GP Putnam’s sons.
Jones, M. R., Fay, R. R., & Popper, A. N. (Eds.). (2010). Music perception. Springer.
Kostka, S. M., Clendinning, J. P., Ottman, R., & Phillips, J. (1995). Tonal Harmony: With an Introduction to Twentieth. McGraw-Hill.
Large, E. W., & Snyder, J. S. (2009). Pulse and meter as neural resonance. Annals of the New York Academy of Sciences, 1169(1), 46-57.
Lerdahl, F., & Jackendoff, R. (1983). An overview of hierarchical structure in music. Music Perception, 229-252.
Lerdahl, F., & Jackendoff, R. (1996). A generative theory of tonal music. MIT press.
London, J. (2012). Hearing in time. OUP USA.
Marques, C., Moreno, S., Luís Castro, S., & Besson, M. (2007). Musicians detect pitch violation in a foreign language better than nonmusicians: Behavioral and electrophysiological evidence. Journal of Cognitive Neuroscience, 19(9), 1453-1463.
McAuley, J. D. (1995). Perception of time as phase: Toward an adaptive-oscillator model of rhythmic pattern processing. (1995)
McAuley, J. D., & Semple, P. (1999). The effect of tempo and musical experience on perceived beat. Australian Journal of Psychology, 51 (3), 176{187.
Ottman, R. W., & Mainous, F. D. (2004). Rudiments of music (p. xiv298). Prentice Hall.
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Phillips-Silver, J., Toiviainen, P., Gosselin, N., Piché, O., Nozaradan, S., Palmer, C., & Peretz, I. (2011). Born to dance but beat deaf: A new form of congenital amusia. Neuropsychologia, 49(5), 961-969.
Rankin, S. K., Large, E. W., & Fink, P. W. (2009). Fractal tempo fluctuation and pulse prediction. Music Perception, 26(5), 401-413.
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Repp, B. H. (2005). Sensorimotor synchronization: A review of the tapping literature. Psychonomic Bulletin & Review, 12(6), 969-992.
Repp, B. H., & Su, Y. H. (2013). Sensorimotor synchronization: A review of recent research (2006–2012). Psychonomic bulletin & review, 1-50.
Schaefer, R. S., Desain, P., & Farquhar, J. (2013). Shared processing of perception and imagery of music in decomposed EEG. NeuroImage, 70, 317-326.
Schellenberg, E. G. (2001). Music and nonmusical abilities. Annals of the New York Academy of Sciences, 930(1), 355-371.
Schellenberg, E. G. (2005). Music and cognitive abilities. Current Directions in Psychological Science, 14(6), 317-320.
Schellenberg, E. G. (2006). Long-term positive associations between music lessons and IQ. Journal of Educational Psychology, 98(2), 457.
Schön, D., Magne, C., & Besson, M. (2004). The music of speech: Music training facilitates pitch processing in both music and language. Psychophysiology, 41(3), 341-349.
Schön, D., Boyer, M., Moreno, S., Besson, M., Peretz, I., & Kolinsky, R. (2008). Songs as an aid for language acquisition. Cognition, 106(2), 975-983.
Scholes, Percy A. (1977). “Form”. The Oxford Companion to Music (10 ed.). Oxford University Press
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Snyder, J. S., & Large, E. W. (2005). Gamma-band activity reflects the metric structure of rhythmic tone sequences. Cognitive Brain Research 24(1), 117-126.
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Woodrow, H. 1909. A quantitative study of rhythm. Arch. Psychol. 14: 1–66.
Zinn, M., & Hogenson, R. (1994). Basics of music: Opus (Vol. 2). Schirmer Books (New York and Toronto and New York).