On Friday, we learnt all about how Alexander Graham Bell invented the telephone. We then created our own string telephones to investigate whether a longer or shorter and tight or loose string would increase the volume of the sound. We found that a tight, short string produced the loudest sound because the sound vibrations had more energy when they reached the ear due to the string being shorter and the sound waves could travel in just one direction in a straight line rather than travelling in lots of different directions.