task3

I. Impulse responses from A to Z

The room which was selected for our measurements is a lecture room in the Chalmers V-building (code VK). This room is intended for speech and is similar to the one we used in the previous labs.

The room impulse responses were measured with the software Room-Capture. Two loudspeaker positions were investigated which correspond to the most usual positions of the teacher. The measures were performed at 5 different positions of microphone in order to cover the whole audience space. Almost all the measurements were done with an omnidirectional electret microphone, and one was done with a binaural microphone. The shape of the room and the 5 positions of microphones can be seen on the sketches above and below (with distances from walls).

- Impulse Response of the room

- Frequency Response

- Impulse response evaluation set

-Impulse response evaluation set metrics

- Convolution with Speech

II. summary

In this work task we investigated the impulses responses of the lecture room with the aid of different microphone and source positions. By analysing visually these impulse responses we got an idea of where the reflections in the room come from and if they are perceived as echoes. Which turned out not to be the truth. Using the impulse responses we calculated the corresponding frequency responses which showed a quite poor performance of the loudspeakers at low frequencies.

With the impulses responses we, furthermore, calculated several parameters which gave us an idea about the sound quality of the room. This one seem to be well design, so to say, for speeches, according to the reverberation time and the definition metrics.

At the end we convolved the speech sample with the impulse responses that we measured at each microphone position. As you will see the convolved speech seems like the real sound that we heard in the lecture hall in each microphone position.