Week 6: Hearing + Perception 2

This week's lecture was based on the following points: the decibel level, localisation (ILD, ITD, Effect of Pinna), Haas, perception vs. measured, psychoacoustics, and Doppler. We began by defining and understanding what decibels are. Decibels are defined as a logarithmic value that expresses the ratio between two quantities. I found it extremely informative to go through the decibel video, which explains how sound can be perceived by humans and what scale is used to calculate decibel levels.

We also went through the dB Full Scale (dBFS), which is the maximum digital level of usable audio before clipping and distortion occur. This is a measurement that can be applied in a real-life live sound context, but also within a studio and recording scenario. The way dBFS helps and supports audio engineers is by providing them with headroom above the 0dB level to accommodate peaks throughout.

In terms of audio, we also went through professional operating level +4dBu and consumer operating level -10dBV. The difference between mic levels and line levels is that a microphone captures sound by converting pressure levels in the air to digital electrical voltage. In terms of internal levels, amps are used to convert instrumental levels to line levels. Microphone levels, instrument levels, line levels, and speaker levels are the various types of levels used in a professional setting. When it comes to comparing and contrasting professional and consumer levels, these two standards differ in the difference between professional audio gear like speakers and monitors and consumer gear like, for example, blue-ray players. These different features can enable audio engineers to compare and contrast their studio production work to what it will sound like on a consumer device such as a car audio system or an MP3 player.

In the last part of today's lesson, we went through psychoacoustics, which is what we hear versus how we can separate different sounds to our conclusive psychological responses. The Shepard tone, named after an American cognitive scientist named Roger Newland Shepard, is a sound made up of a superposition of sine waves separated by octaves. Within the psychoacoustics term, there is also an effect called the cocktail party effect. The cocktail party effect is the ability to focus listening on a particular sound whilst filtering out unwanted sounds. How this is reflected in a real-world context is by having the ability to mix different instruments within a mix without requiring us to solo each instrument.

In terms of localisation in audio, it is known as the sound based on the direction of the first arriving sound. In terms of Interaural Intensity Differences (IID), it is defined as the direction in which high frequencies are perceived. On the other hand, in terms of Interaural Time Differences (ITD), it is defined as the direction in which low-end frequencies are preserved.

How I can reinforce today's learning is by reviewing YouTube videos of the different terms and looking at real-life examples of where these methods are used and can be reflected upon. In terms of my next steps before next week, I will be looking to implement today's learnt terms into my project's two assignment descriptions and audio analysis. My goal will be to compare how different audio recordings differ in SPL levels when using professional-level gear versus consumer-level gear.

In terms of the transferable skills that I feel were best reflected during today's lesson, I strongly believe that they were interpersonal and professional skills. In regards to the interpersonal skills that were reflected today, they are the ability to collaborate with other students within their class discussions. Today's lesson was a very interactive lesson where we interacted with different students to fully understand the different terms that were being taught. Finally, the final transferable skill which I found to be strongly reflected during today's session was time management under professional skills. Today's session required a high level of time management to enable us to intake different points of information being taught, which we were required to understand and continuously reflect upon. The reflection process ensured that we had a clear understanding of what was being said.