Вы услы­ши­те ин­тер­вью два­жды. Вы­бе­ри­те пра­виль­ный ответ 1, 2 или 3.

What did Stan and his partner try to achieve with their experiments?

1)  The creation of new types of speakers.

2)  The effect of producing sound images.

3)  The proper application of old-⁠fashioned objects.