Lesson plan
missing fundamental
, and the second harmonic, 200 hertz. The periodicity is nevertheless clear when compared to the full-spectrum waveform on top. The missing fundamental phenomenon is the perceptual phenomenon of hearing a pitch corresponding to the lowest (fundamental) harmonic when presented with sound made of a set of frequency multiples (overtones), even when it is actually absent. This can be used to simulate lower frequency sounds with speakers that cannot actually play those frequencies, by playing the overtones that are within its range. It is established in psychoacoustics that the auditory system, with its natural tendency to distinguish a tone from another, will persistently assign a pitch to a complex tone given that a sufficient set of harmonics are present in the spectrum. For example, when a note (that is not a pure tone) has a pitch of 100 Hz, it will consist of frequency components that are integer multiples of that value (e.g. 100, 200, 300, 400, 500.... Hz). However, smaller loudspeakers may not produce low frequencies, so in our example, the 100 Hz component may be missing. Nevertheless, a pitch corresponding to the fundamental may still be heard.
Article summary
, and the second harmonic, 200 hertz. The periodicity is nevertheless clear when compared to the full-spectrum waveform on top. The missing fundamental phenomenon is the perceptual phenomenon of hearing a pitch corresponding to the lowest (fundamental) harmonic when presented with sound made of a set of frequency multiples (overtones), even when it is actually absent. This can be used to simulate lower frequency sounds with speakers that cannot actually play those frequencies, by playing the overtones that are within its range. It is established in psychoacoustics that the auditory system, with its natural tendency to distinguish a tone from another, will persistently assign a pitch to a complex tone given that a sufficient set of harmonics are present in the spectrum. For example, when a note (that is not a pure tone) has a pitch of 100 Hz, it will consist of frequency components that are integer multiples of that value (e.g. 100, 200, 300, 400, 500.... Hz). However, smaller loudspeakers may not produce low frequencies, so in our example, the 100 Hz component may be missing. Nevertheless, a pitch corresponding to the fundamental may still be heard.
Key claims
- publication date: 1241 — source: Wikipedia · confidence 0.95
Discussion questions
- Summarise the article in your own words. Which single claim would you verify first, and why?
- The record states that the publication date is "1241". What evidence would count against this claim?
- Which claim in this article is most likely to be revised as the sources update? How would you check its current status?
- If two sources disagreed about one of these facts, what would you need in order to trust one over the other?
Bibliography
- Wikipedia https://en.wikipedia.org/w/index.php?oldid=1368916989
Key claims and bibliography are generated from the same tracked claims and sources as the article page.