Acoustic reviews

Originally inspired by telegraph and telecom domains, the audio industry has seen first uses of the audio equalization with…

There are various components that are included in Hearing Aid devices . The key components that are inside every hearing aid device are a microphone, DSP (Digital Signal Processor), speaker (commonly called a receiver within the industry), a battery, and a shell that encloses all the components. Onsemi serves the Hearing Aid market with DSPs, and electronic peripherals such as EEPROMs, radio ICs, and power management components useful for integrating rechargeable batteries. Onsemi’ solutions are offered as entirely programmable by the customer, called open-programmable products, and fully featured turnkey solutions with algorithms to load on the device, called Preconfigured

Introduction and Working Principle Originating from a setup created by Hermann von Helmholtz in the 1850s for determining sound pitches, this resonator consists of two main parts: a cavity and a neck, structured together as shown in Figure 1. When excited by an acoustical wave, the system will resonate at a frequency 𝑓₀, as given by the formula below, thereby creating an aero acoustic source. Two popular application examples in speaker systems Bass-Reflex Enclosure A Bass-Reflex enclosure (illustrated in Figure 2) typically utilizes Helmholtz resonance to extend the low-frequency response of a speaker system. When examining the electrical input

When integrating a speaker into a device, it is essential to isolate its front radiation space from that of the rear. This is done in practice by building an enclosure dedicated to the transducer. However, by doing so the rear volume of air applied to the speaker becomes an acoustic load acting as a high-pass filter on the system response: the smaller the volume, the more the low frequencies are filtered. Two well-known techniques in the industry for recovering some low frequencies are the Bass-Reflex (BR) and the Passive Radiator (PR), respectively invented by A. L. Thuras in 1932

In noisy environments, accurately picking up sound from a specific location is often a challenge. Since using conventional directive microphones may sometimes not be adequate or sufficient, beamforming techniques are nowadays widely considered in the audio industry. Focusing on 1-dimensional arrays, two well-known arrangements, named Broadside and End-Fire, simply consist of multiple omnidirectional microphones separated by a certain distance (fixed in the simplest cases). For the first configuration (illustrated in Figure 1), microphones are configured perpendicularly to the incoming wave direction, and the simplest audio operation can just be a summation (fixed array case). In the second configuration illustrated

Setup of a plane wave generator with the loudspeaker on the left and the microphone network system under test on the right As we work more and more with multi-microphone networks in our laboratories, such as beamformers, we often want to control acoustic behavior of all the microphones at the same time. One method to accomplish this is a loudspeaker system relatively far from the microphone network so that all wavefronts in the bandwidth of interest are seen as planar by the network. (Figure 2 against Figure 1). In this configuration, all the microphones would receive incoming waves with