  | |
| The way to use hearing aid application |
|---|
Hearing aid application (HAA) is software which, when installed on a mobile computational platform, helps with hearing. [1] Mobile devices may include smartphones, tablets or smart watch.
| | |
| The way to use hearing aid application |
|---|
Hearing aid application (HAA) is software which, when installed on a mobile computational platform, helps with hearing. [1] Mobile devices may include smartphones, tablets or smart watch.
As operational characteristics are adjusted directly through the graphic interface of the application, this feature allows classifying the hardware-software complex as a programmable hearing aid. [2]
HAA, as a rule, adjusts the level of the surrounding acoustic environment (sound) to the user's hearing characteristics, thereby allowing him to hear better. [3] [4] [5] [6] [7] Most of HAA works both with wired and bluetooth headsets/headphones. [5] [6] [7] [8] [9] [10]
Unlike traditional hearing aid, which is a part of system consisting of a hearing aid, wired or wireless interworking interface, computer device and installed software for changes, [2] adjustment of HAA is a procedure within the united hardware-software complex.
| Hearing aid applications | Traditional Hearing aids | |
|---|---|---|
| Channels | Up to 256 | 15-111 |
| Sample rate | Maximum 44 kHz | Maximum 14 kHz |
| Programmable hearing aid | Yes (done by user) | Yes (done by specialist) |
| In-built hearing test | Yes | Yes (limited) |
| Hearing test time | A few minutes (by the user) | 30 minutes - 60 minutes (several times) |
| Effects of anti stigmatization | Yes | No, except for intra channels (CIS) |
| Audio recorder + Speech recognition in text | Yes | No |
| Remote microphone option without additional devices | Yes | No |
| Binaural correction of both ears | Yes | No |
| Gain formula, that takes into account the upper threshold of perception | Yes | No |
| Adjustable noise supppression | Yes | Yes |
| Ecosystem of assistive applications (radio, music player, etc.) | Yes | No |
| Built into app course of adaptation to hearing aid | Yes | No |
| Online gain formula change | Yes | No |
| Amplification of quiet sounds (dynamic compression - WDRC) | Yes | No |
| Batteries | Built-in, rechargeable | Rechargeable and replaceable |
Thus, HAA is not inferior, and even surpasses traditional hearing aids in some characteristics (number of channels, sampling frequency etc.).
The basic hearing aid setting is amplification adjustment in accordance with the user's audiogram.
The process of selection of traditional hearing aid starts with audiometry, which is also the first characteristic of sound perception disorder considered during the adjustment of HAA. If the user has already had a special audiologic checkup, this type of adjustment can be done remotely by a specialist, and the results of this checkup can be entered by the user with the help of the application's graphic interface. A lot of HAA have a built-in procedure of in situ-audiometry which automates the whole process so that the user can take this type of examination on their own. Software-based generators of tone signals and interface elements for reaction to exceeding the hearing perception threshold are used for that.
Quick change of settings, such as recruitment compensation, noise suppression, amplification regulation allows HAA users to choose the settings which are more suitable to understanding the speech in silence or with a background noise.
An additional feature of HAA is ability to choose and apply the sets of parameters most suitable for the current acoustic situation, for example, for silence, for talking in a noisy environment, etc.
Some HAA provide for using different computing formulas for calculation of target amplification on the basis of audiometry data. These formulas are intended to amplify the speech up to the maximum comfortable level of perception by the user. [2]
In particular, Pertalex HAA offers its users 3 well-known formulas:
When using microphone equipment of phone headsets, maximum available amplification is limited by appearance of acoustic feedback between the microphone and the speaker. Increase of possible level of signal amplification is ensured by stronger suppression of acoustic feedback. [14]
Acoustic feedback is the most widespread option of feedback appearing at the return leakage of sound from the speaker to the microphone. This can be caused by small distance between the microphone and the speaker, loose fit of an earpiece to the surface of acoustic meatus and so on.
The processing under frequency-dependent amplification of input signal for compensation of hearing impairment includes assistive functions, such as acoustic feedback suppression. [2]
In a number of HAA a scheme with subband signal decomposition is used for acoustic feedback suppression. [15]
Compared to traditional hearing aids, HAA has the following disadvantages:
At the same time, HAAs has a number of great advantages:
Of the 11 apps tested in the hearing assistant category, all 11 apps were still accessible at the end of the scoring period. The best app in the hearing assistant category was Petralex Hearing Aid (4.3/5). [16] 
Distribution of HAA is limited by the infrastructure of specialized application stores, such as App Store, Google Play, etc. There is a fairly large number of applications that implements a hearing aid based on a smartphone/tablet. However, despite the general idea - hearing aid, they all differ in a number of criteria.
For benchmarking, the following applications were selected from the top 10 Google Play store applications (for Android devices) and the App Store (for iOS devices), selected on the "Hearing aid" request, and meet the following criteria:
Comparative characteristics of hearing aid applications presented on the market are presented in the following table: [17] [18]
Petralex | uSound (Hearing Assistant) | Hearing Aid Sound Amplifier | Fennex | Ear Spy | Jacoti ListenApp | BoiAid | AmplyPhone | Dectone | Listening device - Hearing aid | Google Sound Amplifier | |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Latest release | January 2019 (iOS), January 2019 (Android) | November 2019 (iOS), January 2019 (Android) | December 2018 (iOS) | December 2018 (iOS) | June 2018 (iOS), October 2018 (Android) | October 2018 (iOS) | February 2015 (iOS) | April 2017 (iOS) | October 2018 (Android) | July 2019 (iOS) | July 2019 (Android) |
| Audio latency | 20 ms*** (iOS), 65 ms*** (Android) | 30 ms*** (Android) | 30 ms*** (iOS) | 45 ms*** (iOS) | 35 ms*** (iOS), 360 ms*** (Android) | 20 ms*** (iOS) | 30 ms*** (iOS) | 35 ms*** (iOS) | 65 ms*** (Android) | 30 ms*** (iOS) | |
| Programmable hearing aid | Yes | Yes | Yes | Yes | No | Yes | No | No | Yes | Yes | No |
| In-built hearing test | Yes | Yes | No | Yes | No | Yes***** | No | No | Yes | Yes | No |
| Automatic/manual audiometry | Automatic and manual | Automatic and manual | Manual | Automatic and manual | No | Automatic and manual | No | No | Automatic and manual | Automatic and manual | No |
| Nonlinear hearing aid | Yes | No | No | No | No | No | No | No | Yes | Yes | No |
| Amplification of quiet sounds (dynamic compression - WDRC) | Yes | No | No | Yes | No | No | No | No | Yes | Yes | Yes |
| Adjustment of WDRC | Yes | No | No | Yes | No | No | No | No | Yes | Yes | Yes |
| Online gain formula change | Yes | No | No | No | No | No | No | No | Yes | Yes | No |
| Ability to adapt to the environment | Yes | Yes | Yes | Yes | No | Yes | Yes | No | Yes | Yes | No |
| Adjustable noise suppression | Yes | No | Yes | Yes | No | No | Yes | No | Yes | Yes | Yes |
| Suppression of acoustic feedback | Yes | No | No | No | No | No | No | No | Yes | Yes | No |
| Bluetooth headset support | Yes, on iOS and Android | Yes, on iOS and Android | Yes, only on iOS | Yes, only on iOS | Yes, on iOS and Android**** | No | Yes, only on iOS | No | Yes | Yes | No |
| Audio recorder | Yes | No | No | No | Yes**** | No | No | Yes | Yes | Yes | No |
| Speech recognition in text | Yes, only on iOS | No | No | No | No | No | No | No | No | Yes | No |
| Volume balance reconstruction of the left/right ear | No | No | Yes | Yes | No | No | No | No | Yes | Yes | Yes |
| Gain formula, that takes into account the upper thresholds of perception | Yes | No | No | No | No | No | No | No | Yes | Yes | No |
| Ecosystem of assistive applications | Yes | No | No | No | No | No | No | No | Yes | Yes | No |
| Built into course of adaptation to hearing aid application | Yes | No | No | No | No | No | No | No | Yes | No | No |
| Special gain formula for tinnitus | Yes | No | No | No | No | No | No | No | Yes | Yes | No |
| Ratings | 4.7 on AppStore, 4.0 on Google Play | 3.7 on Google Play | 4.4 on AppStore | No | 3.1 on AppStore, 3.7 on Google Play | No | No | No | 3.7 on Google Play | 4.6 on AppStore | 3.7 on Google Play |
Notes: *tested on iPhone 6+ (iOS 9.2), ** tested on Samsung Galaxy A3 (Android 7.0), *** on the date of testing (11 February 2019), **** in the paid version, ***** - with the help of an additional application.
The principles of working HAA are similar to those of traditional hearing aids.
Most HAA provides two modes: settings mode (passing through the in situ-audiometry procedure) and the hearing correction mode.
Setup mode is an in situ-audiometry procedure that allows the user to independently measure hearing thresholds using tone audio signals that are generated with a gradually increasing amplitude over a period of some seconds. Audio signals are generated according to the following sequence of frequencies: 125, 250, 500, 1000, 2000, 4000, 6000 and 8000 Hz.
Some HAA do not have an integrated audiometry system. In this case, the adjustment of the sound amplification level (similar to the equalizer) is made by the user based on their own subjective feelings. [9] [10] [19] [20]
Hearing correction mode represents an audio signal processing system. The audio signal processing system implements a broadband method for changing the correction of the spectral envelope of a signal using a filter with a finite impulse response whose frequency response is generated based on user-defined hearing thresholds during the in situ-audiometry procedure.
Figure 2 shows a general signal processing scheme in a hearing aid application.
Audio input signal, acoustic feedback (echo) and background noise are captured by the microphone, summed and then divided into sub-band components with a lower sampling rate using an analysis filter bank (AFB).
Estimation of noise is based on the minima controlled recursive averaging of past values of noise. [21]
Cleared of noise subband signal is cleared of acoustic echo by adaptive filtering. [21]
The subband audio components that are cleared of echo and noise are amplified by multiplying by the corresponding coefficients, which are calculated based on the level of input and output audio signals, ambient noise energy, as well as hearing thresholds (hearing loss frequency characteristics) of the user.
The gain unit also performs the function of dynamic range compression, thereby compensating for the function of non-linear amplification of the human cochlea.
The processed broadband signal is synthesized using a synthesis filter bank (SFB).
AFB and SFB can be realised as DFT-modulated filter banks, which is one of the most popular filter bank type used in modern hearing aids. [21]
The output signal can be multiplied by the total gain, which provides a comfortable sound level. This coefficient is adjusted by the user using an external controller directly in HAA interface. [9] [4] [5] [6]
HAA, as a rule, provides high speed (i.e. minimum sound delay) and high sound quality due to a simple signal processing algorithm as well as due to the effective implementation of application functional blocks. [21]
Some HAA may not have an acoustic cancellation block. [22]
Based on the results of studies conducted on the effectiveness of using the different hearing aid applications, it can be concluded that for those respondents who have never used hearing aids before, there is a tendency of a positive effect on speech intelligibility. The positive impact on speech intelligibility when talking in a noisy environment was noted by those respondents who used hearing aids. [23]
HAA also can be useful not only as a hearing aid. For example, it can be useful in the process of studying, as students can place their smartphone/tablet closer to the teacher and hears him better. [8]
In sound recording and reproduction, and sound reinforcement systems, a mixing console is an electronic device for combining sounds of many different audio signals. Inputs to the console include microphones being used by singers and for picking up acoustic instruments, signals from electric or electronic instruments, or recorded music. Depending on the type, a mixer is able to control analog or digital signals. The modified signals are summed to produce the combined output signals, which can then be broadcast, amplified through a sound reinforcement system or recorded.
A hearing aid is a device designed to improve hearing by making sound audible to a person with hearing loss. Hearing aids are classified as medical devices in most countries, and regulated by the respective regulations. Small audio amplifiers such as PSAPs or other plain sound reinforcing systems cannot be sold as "hearing aids".
A hearing test provides an evaluation of the sensitivity of a person's sense of hearing and is most often performed by an audiologist using an audiometer. An audiometer is used to determine a person's hearing sensitivity at different frequencies. There are other hearing tests as well, e.g., Weber test and Rinne test.
A sound reinforcement system is the combination of microphones, signal processors, amplifiers, and loudspeakers in enclosures all controlled by a mixing console that makes live or pre-recorded sounds louder and may also distribute those sounds to a larger or more distant audience. In many situations, a sound reinforcement system is also used to enhance or alter the sound of the sources on the stage, typically by using electronic effects, such as reverb, as opposed to simply amplifying the sources unaltered.
Audiometry is a branch of audiology and the science of measuring hearing acuity for variations in sound intensity and pitch and for tonal purity, involving thresholds and differing frequencies. Typically, audiometric tests determine a subject's hearing levels with the help of an audiometer, but may also measure ability to discriminate between different sound intensities, recognize pitch, or distinguish speech from background noise. Acoustic reflex and otoacoustic emissions may also be measured. Results of audiometric tests are used to diagnose hearing loss or diseases of the ear, and often make use of an audiogram.
A portable media player (PMP) or digital audio player (DAP) is a portable consumer electronics device capable of storing and playing digital media such as audio, images, and video files. The data is typically stored on a compact disc (CD), Digital Video Disc (DVD), Blu-ray Disc (BD), flash memory, microdrive, or hard drive. Most portable media players are equipped with a 3.5 mm headphone jack, which users can plug headphones into, or connect to a boombox or hifi system. In contrast, analogue portable audio players play music from non-digital media that use analogue signal storage, such as cassette tapes or vinyl records.
A sound level meter is used for acoustic measurements. It is commonly a hand-held instrument with a microphone. The best type of microphone for sound level meters is the condenser microphone, which combines precision with stability and reliability. The diaphragm of the microphone responds to changes in air pressure caused by sound waves. That is why the instrument is sometimes referred to as a Sound Pressure Level (SPL) Meter. This movement of the diaphragm, i.e. the sound pressure deviation, is converted into an electrical signal. While describing sound in terms of sound pressure (Pascal) is possible, a logarithmic conversion is usually applied and the sound pressure level is stated instead, with 0 dB SPL equal to 20 micropascals.
Adaptive feedback cancellation is a common method of cancelling audio feedback in a variety of electro-acoustic systems such as digital hearing aids. The time varying acoustic feedback leakage paths can only be eliminated with adaptive feedback cancellation. When an electro-acoustic system with an adaptive feedback canceller is presented with a correlated input signal, a recurrent distortion artifact, entrainment is generated. There is a difference between the system identification and feedback cancellation.
Analysis of sound and acoustics plays a role in such engineering tasks as product design, production test, machine performance, and process control. For instance, product design can require modification of sound level or noise for compliance with standards from ANSI, IEC, and ISO. The work might also involve design fine-tuning to meet market expectations. Here, examples include tweaking an automobile door latching mechanism to impress a consumer with a satisfying click or modifying an exhaust manifold to change the tone of an engine's rumble. Aircraft designers are also using acoustic instrumentation to reduce the noise generated on takeoff and landing.
Audio signal flow is the path an audio signal takes from source to output. The concept of audio signal flow is closely related to the concept of audio gain staging; each component in the signal flow can be thought of as a gain stage.
An assistive listening device (ALD) is part of a system used to improve hearing ability for people in a variety of situations where they are unable to distinguish speech in noisy environments. Often, in a noisy or crowded room it is almost impossible for an individual who is hard of hearing to distinguish one voice among many. This is often exacerbated by the effect of room acoustics on the quality of perceived speech. Hearing aids are able to amplify and process these sounds, and improve the speech to noise ratio. However, if the sound is too distorted by the time it reaches the listener, even the best hearing aids will struggle to unscramble the signal. Assistive listening devices offer a more adaptive alternative to hearing aids, but can be more complex and cumbersome.
Equalization is the process of adjusting the balance between frequency components within an electronic signal. The most well known use of equalization is in sound recording and reproduction but there are many other applications in electronics and telecommunications. The circuit or equipment used to achieve equalization is called an equalizer. These devices strengthen or weaken the energy of specific frequency bands or "frequency ranges".
In live sound mixing, gain before feedback (GBF) is a practical measure of how much a microphone can be amplified in a sound reinforcement system before causing audio feedback. In audiology, GBF is a measure of hearing aid performance. In both fields the amount of gain is measured in decibels at or just below the point at which the sound from the speaker driver re-enters the microphone and the system begins to ring or feed back. Potential acoustic gain (PAG) is a calculated figure representing gain that a system can support without feeding back.
The first hearing aid was created in the 17th century. The movement toward modern hearing aids began with the creation of the telephone, and the first electric hearing aid was created in 1898. By the late 20th century, the digital hearing aid was distributed to the public commercially. Some of the first hearing aids were external hearing aids. External hearing aids directed sounds in front of the ear and blocked all other noises. The apparatus would fit behind or in the ear.
Personal Sound Amplification Products, also known as "Personal Sound Amplification Devices," or by the acronym PSAP, are defined by the U.S. Food and Drug Administration as wearable electronic products that are intended to amplify sounds for people who are not d/Deaf or Hard of Hearing. They are not hearing aids, which the FDA describes as intended to compensate for hearing loss. According to Dr. Mann of the FDA, choosing a PSAP as a substitute for a hearing aid can lead to more damage to your hearing
Assistive Technology for the Deaf and Hard of Hearing is special technology made to assist them including Hearing aids, Video relay services, tactile devices, alerting devices and technology for supporting communication.
Here One is a pair of wireless smart earbuds developed and manufactured by Doppler Labs. It allows users to filter sound, stream music, and amplify speech. It can also be used to take phone calls and filter certain sounds, such as background noise. Here One has been called the world’s first in-ear computer and in June 2018 Here One was inducted into the Smithsonian Institution's Copper Hewitt Museum of Design for innovation in audio technology.
In sound technology, personalised sound refers to a range of technologies that customise an audio device's sound output to match the listener's hearing sensitivities or their environment.
AirPods Pro are wireless Bluetooth earbuds created by Apple, initially released on October 30, 2019. They are Apple's mid-range wireless earbuds, sold alongside the base-level AirPods and highest-end AirPods Max.
"Petralex" is a hearing aid application for smartphones and tablets that implements a digital hearing aid with a built-in in situ-audiometry procedure. This application takes into account the ambient sound environment and independently adjusts to the user's ear. Petralex was developed by IT4YOU corporation for smartphones and tablets with Android and iOS operating systems and is distributed free of charge through the Donationware system.