Introduction
For this work progress 3, I focused on methodology. This work progress comprises of 4 components which are flowchart, gantt chart, visitting Acoustic Lab and Priliminary Result
Project Flowchart
Gantt chart for FYP1 and FYP2
Visitting Acoustic Lab
On 20th January, I visited Acoustic lab to get more understanding regarding room acoustics. Here is the outcomes that I gathered from visitting Acoustic Lab
Figure 1: Absorption Room
Figure 2: Reverberant Room
Figure 1 shows the absorption room while figure 2 shows the reverberant room. The observation that have been made is when we clap our hands in absorption room, the sound will not have any echo because the wall is made of soft materials. While in reverberant room, the wall is made of rough materials, so the sound will produce more echos. In my observation, when echos is produced, it is hard for me to catch what is Dr talking in the reverberant room while in absorption room, I can hear clearly what Dr is saying. Below is the equipment that I will used during my research.
Figure 3: Digital Audio Tape
Figure 4: Larson Davis impulsive noise source Model BAS006
Priliminary Result
I have search the coding that I can use to convert .wav file to sound pressure level to analyze the sound reflection patterns. I got the code from this url: https://www.mathworks.com/matlabcentral/answers/757874-how-to-calculate-sound-level-spl-audio-file-wav.
I have done priliminary results by observing the sound reflection pattern in my room. I have taken the audio signal from my phone and converted using the codings I got. The sound source is clapping hands and I captured the sound signal by varies the distance at 2m, 4m, and 6m from the sound source. Below is the codings and the results.
Figure 1: Coding for SPL
Figure 2: Results of 2m from source
Figure 3: Result of 4m from source
Figure 4: Result of 6m from source
The observation is the nearer location from sound source, the shorter the sound decay. Shorter sound decay gives lower reverberation time (RT60). Lower reverberation time cause higher speech intelligibility. The further location from sound source, the longer the sound decay. Longer sound decay gives higher reverberation time (RT60). Higher reverberation time cause lower speech intelligibility.