Acoustics

Events

Lange Nacht der Wissenschaft (Night of Science)

Fr, 09/24/2010 

Within the event "Lange Nacht der Wissenschaft" (Night of Science) at the Universitiy of Oldenburg the Acoustics and the Neuroacoustics group joined forces to present their field of research to the visitors. The labs have been opened to show the current topics of research as well as basics in acoustics.

Standing Waves

BildUsing a "Kundtsches Rohr" filled with propane, standing waves have been visualised to the visitors. A loudspeaker presented a constant tone into the pipe. The sound wave is reflected at the end of the pipe and is superposing with itself. At wave nods almost no propane is streaming out of the pipe and the flames are small. At wave bulges the gas moves strongly in the pipe and more of it is streaming out, so that the flames are bigger at the bulges, which can be seen in the picture.

 

Pulse Responses

BildHow does your voice sound when you are in a bottle? This can easily be demonstrated by using pulse responses. Once recorded for a special room like a wooden box or a large hall, a pulse response can be combined with every acoustic signal you can think of. After a convolution with the pulse response of a room, the recorded signal will sound as if it has been recorded in that special room. During the evening the visitors could experience this phenomenon with their own voices. A sentence has been recorded live and convulated with different pulse responses. Over loudspeakers the visitors then could here themselves for example from a church with a long echo, as if they are trapped in the bottle which can be seen in the middle of the picture or talking with their head in the dustbin.

 

Anechoic room

BildThis room has walls which can be seen but cannot be heard. Due to the long foam wedges at every wall and also the floor and the ceiling, almost no sound is reflected from the walls. Therefore the room is also called "Free-field", because its acoustical properties are the same as for a free field outdoors. The visitors could experience this  special acoustical enviroment  shown in the  picture during the evening. A semi-circle of loudspeakers has been used to present sounds from multiple directions. A piece of music has been arranged to demonstrate spatial hearing. In addition a psycho-acoustical experiment has been performed with the visitors which clarified the advantages of hearing with two ears.

 

Vibration Lab

Bild Alongside to the presentations at the anechoic chamber, the vibration laboratory from the Acoustics Group has been presented. In this laboratory, it is possible to extend acoustical environments with whole body vibration. This allows, for example, to realistically simulate driving a car. The vistiors were able to experience vibration while sitting on a test bench with a simple chair. In addition it was possible to be a part of a vehicle simulation combining sound and vibration, while having the impression of sitting in a real car.