Cast
Dr Helen Czerski examines the world of sound waves.
Helen Czerski (Acting)
14 August 2020
17 April 2011
1 October 2006
6 November 2021
24 September 1999
22 September 1994
27 March 2005
6 May 2019
30 August 2022
15 July 2016
2 December 2013
17 December 1989
8 February 2015
3 March 2013
14 December 2015
15 January 2021
31 October 2010
23 November 2022
20 January 2008
24 March 2005
2 March 2017
