The impact of sound on film style

This post is the last of three draft papers that apply statistical analysis to questions of film style. This I focus on the impact of sound technology on shot length distributions by examining the change in the median shot length and the interquartile range. You can access the pdf here: Nick Redfern – The impact of sound technology on Hollywood film style, and the abstract is presented below.

Quantitative analyses of the impact of sound technology on shot lengths in Hollywood cinema have claimed that, with the coming of sound, the mean shot length increased from ~5s to ~11s, and that this indicates a major change in film style as cutting rates slowed. However, the mean shot length is not a robust statistic of film style due to the positive skew of the data and the presence of outlying data points in shot length distributions. The median shot length is shown to be a more robust statistic unaffected by shape of shot length distributions, and the impact of sound technology on Hollywood is analysed through looking at the median shot lengths of silent films produced between 1920 and 1928 (n = 20, median = 4.4s [95.86% CI: 3.7, 5.1]) and sound films produced from 1929 to 1931 (n = 30, median = 6.9s [95.72% CI: 5.9, 8.7]). The results show that there is an increase in shot lengths in the early sound era (Mann-Whitney U = 33.5, p = <0.0001, PS = 0.0558), but that this change is much less than that described by studies using the mean shot length (HLΔ = 2.9s [95% CI: 1.8, 4.1]). Looking at the interquartile ranges of the silent films (median = 4.8s [95.86% CI: 4.3, 5.7]) and the sound films (median = 10.7s [95.72% CI: 8.8, 12.1]), we see that there is an increase by HLΔ = 5.5 seconds (95% CI: 4.1, 7.1), indicating that shot lengths in sound films show greater variation than those of the silent era (Mann-Whitney U = 4, p = <0.0001, PS = 0.0067).

As before, I’ll leave this up for a while before submitting it to a journal (if I can find one), so feel free to comment.

UPDATE (07/07/2010): this paper has been updated to take into account a flaw in one of the data sets used, and this has led to a minor revision of the results. The figures for U and PS for the difference between the median shot lengths have both been revised up by a factor of 1/600, so that U is now 33.5 and not 32.5, and PS = 0.0558 instead of 0.0542. The value of HLΔ for the interquartile ranges has been revised down from 5.6s to 5.5s.

About Nick Redfern

I am an independent academic with over 15 years experience teaching film in higher education in the UK. I have taught film analysis, film industries, film theories, film history, science fiction at Manchester Metropolitan University, the University of Central Lancashire, and Leeds Trinity University, where I was programme leader for film from 2016 to 2020. My research interests include computational film analysis, horror cinema, sound design, science fiction, film trailers, British cinema, and regional film cultures.

Posted on September 24, 2009, in Cinemetrics, Film History, Film Studies, Film Style, Hollywood, Silent cinema and tagged , , , , , . Bookmark the permalink. 9 Comments.

  1. You are being less than honest here, by concealing the fact that in another of your pieces here, you found that of a sample of 43 films, no less than 24 fitted the Lognormal distribution well. Since none of the other authors you quote have tested the Lognormal distribution on film shot lengths, there is every reason to suppose that it is the ruling distribution in this area. The main point of this paper is largely pointless, because since the mean for Lognormal distributions is given by the relation Mean = Median*exp(0.5(shape factor)^2)), and for most films the shape factor is about 0.9, then Median ~ 0.6 Mean.
    Hence the difference between the Median shot lengths for sound and silent films with be 0.6 times the difference between the Mean shot lengths for sound and silent films, particularly when calculated for a fairly large population, which will tend to iron out the more deviant values.

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