Sound of Silence, The / Subtracting Sound

Synopsis

1: Periodic sounds such as tones, including those from musical instruments, can be mathematically modelled as sine waves. Computer-generation animations and the facilities of the BBC Radiophonic Workshop are used to illustrate how 1) the pitch and loudness of periodic sounds correspond to the frequency and amplitude of sine waves; 2) sound waves can be added together producing beats or harmonics; 3) waves can be phase-shifted and that adding two out-of-phase periodic sound waves can produce silence.
2: Complex sounds can still be recognised even when some frequencies or harmonics are removed. Shows: 1) the wave form and sound of a square wave and the results of filtering out the harmonics; 2) how telephones cut off most of the high and low frequencies present in the human voice.

Series

Mu120 Videocassette 2

Language

English

Country

Great Britain

Medium

Video; Videocassette. Standard formats. col. 19 min.

Year of production

1996

Availability

Sale

Subjects

Mathematics; Music; Physics

Keywords

mathematical modelling; music theory; sounds; waves

Credits

Producer

Jean Nunn

Cast

Carol Bolt
John Hunt

Sections

Title

Sound of silence, The

Synopsis

1: Periodic sounds such as tones, including those from musical instruments, can be mathematically modelled as sine waves. Computer-generation animations and the facilities of the BBC Radiophonic Workshop are used to illustrate how 1) the pitch and loudnes

Title

Subtracting sound

Synopsis

2: Complex sounds can still be recognised even when some frequencies or harmonics are removed. Shows: 1) the wave form and sound of a square wave and the results of filtering out the harmonics; 2) how telephones cut off most of the high and low frequencie

Production Company

Name

BBC Open University Productions

Distributor

Name

Open University Worldwide

Web

http://www.ouw.co.uk External site opens in new window

Phone

+44 (0) 1908 274066

Address

Walton Hall
Milton Keynes
MK7 6AA

Notes

NB. As of May 2016 Open University Worldwide are no longer distributing DVDs. They have posted this message on their website: ‘Unfortunately Open University Worldwide Limited has decided that product sales are no longer viable given the reduced funding to Higher Education institutions and diminishing demand for the products we have traditionally stocked. At present the Open University Students Association (OUSA) will continue to sell the "Good Study Guide", and we are in discussion with other possible distributors to continue to make The Open University’s products available for purchase. As soon as we have any information on other channels of distribution we will update this notice’. Some products are still available via second hand dealers on Amazon.co.uk