Diffuse Field Acoustic Testing (DFAT) is a method used primarily in the field of acoustics and material testing to evaluate the sound absorption and sound scattering properties of materials in a space where sound waves are diffused uniformly. This technique involves taking measurements in a controlled environment where the sound field is diffuse, meaning that sound waves are coming from multiple directions, which mimics real-life acoustic environments.

Physical acoustics is a branch of acoustics that focuses on the study of sound waves, their propagation, and their interactions with different media. It involves the application of the principles of physics and engineering to understand sound in various environments and contexts. Here are some key areas of focus within physical acoustics: 1. **Wave Propagation**: Understanding how sound waves travel through different materials, including gases, liquids, and solids. This includes studying factors like speed, frequency, wavelength, and attenuation.

Helmholtz resonance, named after the German physicist Hermann von Helmholtz, refers to a phenomenon related to the resonant frequency of a cavity and its connection to the surrounding air. It typically arises in systems where a gas-filled cavity (such as a bottle or a hollow object) has a neck or opening that allows air to flow in and out. In simple terms, a Helmholtz resonator can be visualized as a container of air with an opening.

A micro perforated plate (MPP) is a type of panel characterized by having a large number of small holes or perforations distributed evenly across its surface. These holes are typically much smaller in diameter compared to regular perforated plates, and the hole size can range from a few micrometers to a few millimeters.

The Minimum Audibility Curve (MAC) is a graphical representation that depicts the threshold of hearing for a typical human ear across different frequencies. Essentially, it shows the quietest sound levels (in decibels) that can be heard by an average listener at various frequencies, typically ranging from about 20 Hz to 20 kHz, which represents the average human hearing range.

A noise barrier, also known as a sound barrier or acoustic barrier, is a structure designed to reduce the impact of noise pollution from sources such as highways, railways, industrial areas, and other loud environments. These barriers are typically constructed from materials that absorb or reflect sound waves, thus preventing them from traveling beyond the barrier.

Submarine signals refer to a variety of acoustic signals used in underwater communication and research. These signals are typically transmitted through water and can be used for various purposes, including: 1. **Sonar Communication**: Submarines and underwater vehicles use sonar (Sound Navigation and Ranging) to communicate and detect objects in their environment. This involves sending sound waves and listening for echoes.

"Presence" in the context of sound recording refers to the quality of a sound that makes it feel immediate and immersive. It is often characterized by clarity, detail, and the sense that the sound source is right in front of the listener rather than distant or artificial. This quality can be influenced by various factors, including recording techniques, microphone placement, the acoustics of the recording environment, and the equipment used.

Smaart is a sophisticated audio analysis software often used in the fields of sound engineering, live sound, and acoustics. Developed by the company EAW (Eastern Acoustic Works), it is primarily known for its capabilities in real-time sound measurement and analysis. Smaart allows users to analyze audio signals, measure sound levels, and assess room acoustics, making it an essential tool for audio professionals involved in live sound reinforcement, installation, and system tuning.

"Sonic philosophy" can refer to a few different concepts, depending on the context in which it is being discussed. Here are a few interpretations: 1. **Philosophy of Sound**: In a broader sense, sonic philosophy may involve exploring the nature of sound, its properties, and its impact on human experience. This can include discussions on how sound influences emotions, perception, and even consciousness.

Salford Acoustics is a consulting firm that specializes in acoustics, noise, vibration, and environmental assessments. Typically, such firms provide services related to architectural acoustics, environmental noise assessments, sound insulation, and vibration analysis for a variety of projects, including residential, commercial, and industrial developments. The company may work on projects like acoustic design for buildings, noise impact assessments for new developments, and providing expert advice on minimizing noise pollution.

The "scale of harmonics" generally refers to a system of musical tuning and scales based on harmonic series and their relationships. In music theory, harmonics are overtones or frequencies that are integer multiples of a fundamental frequency. The harmonic series starts with the fundamental frequency (the first harmonic) and continues with higher frequencies, which are the second harmonic (2 times the fundamental), third harmonic (3 times the fundamental), and so on.

In acoustics, the term "sweet spot" refers to a specific location within a listening environment where sound quality is optimized. This spot is typically where the listener experiences the best balance of sound characteristics, such as clarity, volume, and spatial imaging.

A Sound Retrieval System (SRS) typically refers to a technology or process used to enhance audio playback and improve sound quality for various applications, including music, movies, and gaming. It often involves algorithms and signal processing techniques designed to create a more immersive and lifelike audio experience. In a broader sense, SRS can also pertain to systems that manage and retrieve sound data for various purposes, such as audio libraries, digital asset management, or even machine learning applications that involve audio analysis and classification.

Sound Amplification by Stimulated Emission of Radiation (SASER) is a process that is analogous to the operation of a laser, but instead of light, it amplifies sound waves. The concept of SASER is based on the principle of stimulated emission, which is the fundamental principle behind laser technology. In a SASER, a medium (often a crystal or a gas) is energized to create a population inversion, where more particles are in an excited state than in the lower energy state.

A sound generator is a device or software that produces sounds or audio signals. Sound generators can be used in various applications, including music production, sound design, environmental sound creation, and acoustic research. They can create a wide range of sounds, from simple waveforms like sine, square, and triangle waves to complex sounds that mimic real instruments or environmental noises. Here are a few types of sound generators: 1. **Analog Synthesizers**: These use analog circuitry to generate sound waves.

Spectral splatter refers to an artifact that can occur in digital signal processing, particularly in the context of audio and image processing. It describes the unintended spreading or smearing of signal components across the frequency spectrum, typically due to nonlinearities, quantization errors, or insufficient sampling rates. In audio processing, for example, spectral splatter can manifest when certain frequencies interact in ways that produce unwanted harmonics or overtones, often as a result of dynamic range compression, distortion effects, or clipping.

Throat singing, also known as overtone singing, is a vocal technique that allows a singer to produce multiple pitches simultaneously. It is characterized by a fundamental pitch (the main tone) alongside one or more overtones that are shaped by resonating in the throat, mouth, and other parts of the vocal tract. This unique singing style is practiced in various cultures around the world, with notable traditions in Mongolia and Tuva, where it is often referred to as "Hoomii".

Acoustoelastography is a medical imaging technique that combines ultrasound and elastography to assess the mechanical properties of tissues, particularly their elasticity and stiffness. This method provides valuable information about tissue characteristics, which can aid in the diagnosis and monitoring of various conditions, particularly in oncology (e.g., tumor characterization) and liver fibrosis assessment. The key components of acoustoelastography include: 1. **Ultrasound Imaging**: Provides real-time imaging of tissues to visualize structure and morphology.

A tuning fork is a metallic instrument that produces a specific pitch when struck. It consists of a U-shaped fork with two prongs and is typically made of steel. When the fork is struck against a surface, it vibrates and creates sound waves at a precise frequency, which is determined by the length and mass of the prongs.