Perception in an auditory context refers to the conscious process in which the brain interprets acoustic stimuli and translates them into sensory impressions. It includes detection, discrimination and cognitive processing of volume, pitch and timbre. Auditory perception is closely linked to attention and memory, which enables complex tasks such as understanding speech in noise. Disorders, such as central auditory processing disorders, occur despite normal peripheral function. Rehabilitative training programs improve perceptual performance through targeted practice of multisensory integration.

A sound transducer (loudspeaker, headphones or bone conduction transducer) converts electrical signals into acoustic waves and vice versa. In audiometry, calibrated transducers are used to ensure defined sound pressure levels at test frequencies. The quality and linearity of the transducer determine the precision of hearing threshold measurements and OAE detection. Miniature transducers (receivers) are integrated into hearing aids, which emit speech signals directly into the ear canal. Transducer designs optimize frequency response, low distortion and energy consumption.

The waiting area is a soundproofed anteroom in front of the measurement booth where patients are prepared acoustically and psychologically before the test. It minimizes the influence of door noises and ambient noise on the test conditions. There are usually control panels for the audiologist and visual communication equipment for the patient. A correctly designed waiting area is part of the standard requirements (DIN standards) for audiology laboratories. It is also used to explain test procedures and to reassure patients before tests.

The Weber test is a simple tuning fork test for the lateralization of bone conduction sound. The vibrating fork is placed in the middle of the crown of the head or the frontal bone; the patient indicates in which ear they hear the sound louder. In the case of conductive hearing loss, the sound lateralizes into the diseased ear, in the case of sensorineural hearing loss into the healthy ear. The Weber test complements the Rinne test for differentiating between conductive and sensorineural hearing loss. It can be carried out quickly and initiates targeted further diagnostics.

Modern hearing aids offer several programs (e.g. quiet, restaurant, music) that adjust acoustic parameters such as compression and microphone characteristics. Programs can be changed manually using buttons on the device, via remote control or automatically using environmental analysis. Automatic program changes detect acoustic scenarios and adapt seamlessly to optimize speech intelligibility and comfort. Training the user to change programs improves self-management and hearing satisfaction. Log files document program change frequency for fine-tuning.

Reciprocal hearing loss refers to a situation in which both ears are hard of hearing, but to different degrees or of different types (e.g. one ear conductive, the other sensorineural). This asymmetry affects lateralization ability and binaural processing. Audiologically, separate air and bone conduction curves of both ears are recorded and masked during tests to avoid cross-hearing. Treatment strategies must adjust each ear individually and ensure binaural synchronization. Asymmetrical loss requires special attention to directional microphone and compression parameters.

Soft cerumen is a moist, usually yellowish form of earwax that is easier to remove from the ear canal than hard, dark cerumen. It is caused by high activity of the cerumen glands and can lead to the formation of plugs if produced excessively. Treatment is carried out with cerumen-dissolving drops (e.g. oil or water-based) and gentle rinsing. Regular checks prevent blockages and conductive hearing loss. In hearing aid fittings, soft cerumen can promote feedback if earmolds do not fit tightly.

White noise contains all audible frequencies with the same power and is perceived psychoacoustically as a uniform "hissing" sound. It is used in hearing therapy as a mask for tinnitus and in sleep aids to promote relaxation. In audiometry, white noise helps as a competing masker in speech audiometry. Technically, it is used to calibrate loudspeakers and microphones to identify frequency response deviations. White noise can lead to hearing damage at excessive volumes.

The waveform represents the sound pressure or electrical signal voltage over time and shows amplitude, period and pulse characteristics. In audiometry, waveforms of clicks and tones are visualized for quality assurance of stimuli. Waveform analysis helps to detect artifacts and distortions and to make stimulus adjustments. In signal processing, time and frequency domain analysis (Fourier transformation) is used for diagnosis and filter development. Clear waveforms are a prerequisite for reproducible measurements of evoked potentials.

The wavelength is the spatial distance between two consecutive in-phase points of a sound wave, calculated as the speed of sound divided by frequency. High frequencies have short wavelengths and are more directional, which is important for localization cues. Wavelength comparison in the head area creates interaural differences that the brain uses to recognize direction. In room acoustics, wavelengths influence the effectiveness of absorbers and diffusers; low frequencies with long wavelengths are more difficult to attenuate. Knowledge of wavelengths is essential for loudspeaker placement and acoustic design planning.

A waveguide conducts sound or electromagnetic waves in a defined direction with minimal energy loss. In audiology, acoustic waveguides are used when hearing tubes or hearing aids are used to bundle sound and guide it to the eardrum. Technical waveguides in hearing aids shape the sound field at the microphone input in order to achieve a directional effect. The dimensions and material of the waveguide determine the cut-off frequency and attenuation. Optimized waveguides improve the signal-to-noise ratio and speech intelligibility.

Resistive impedance is the real component of acoustic or electrical impedance that describes energy loss due to friction or ohmic resistance. In middle ear mechanics, it corresponds to the damping properties of the ossicular chain and membranes. In tympanometry, an increased resistance component influences the shape of the impedance curve and indicates stiffening or fluid. In hearing aid circuits, low resistance reduces noise and improves energy efficiency. Impedance matching minimizes reflections at interfaces.

Wind noise reduction is a signal processing function in hearing aids and microphones that detects and reduces turbulent sound from wind at the microphone opening. Algorithms detect characteristic low-frequency components and activate adaptive filters or microphone switching. This improves speech intelligibility outdoors without manual intervention. Mechanical wind deflectors (foam caps) supplement the digital suppression. Effectiveness is verified in real field tests at various wind speeds.

A windscreen is a physical cover (e.g. foam, fur) that is placed over microphones or speakers to dampen wind noise. It prevents turbulent air movement at the microphone inlet and reduces low-frequency noise. Windscreen materials are acoustically transparent for speech frequencies, but attenuate disruptive air pressure peaks. In hearing aids and audio recorders, it increases recording quality under free-field conditions. Regular replacement prevents contamination and material wear.

The angle of sound refers to the direction from which a sound source arrives relative to the body or device axis. Binaural cues such as interaural time and level differences encode this angle in the auditory system. Hearing systems with multi-microphone arrays reconstruct sound angles to adaptively control directional microphones. Measurements in the sound field determine directional characteristics and frontal gain. Precise angle determination improves localization and speech intelligibility in complex environments.

Efficiency in hearing aid technology describes the ratio of acoustic output power to electrical input power. High efficiency means longer battery life and less heat generation. Influencing factors are microphone sensitivity, amplifier circuits and receiver efficiency. Manufacturers optimize circuit topologies and components to achieve efficiencies of >50%. Efficiency is particularly important for small in-ear systems with limited space and battery.

An active amplifier is an amplifier circuit that takes over the main part of the sound amplification in hearing aids. It follows preamplifier and filter stages and drives the loudspeaker (receiver). Characteristics such as linearity, noise figure and distortion factor determine sound quality and listening comfort. Modern active amplifiers integrate feedback suppression and dynamic compression. Optimized layouts minimize disruptive effects and electromagnetic interference.

A word discrimination test examines how well test subjects can distinguish between similar words by listening to minimal pairs ("comb" vs. "can"), for example. It measures central processing performance and language comprehension beyond the pure hearing threshold. Results help to identify specific deficits in consonant or vowel differentiation. Test environments vary the signal-to-noise ratio to simulate everyday situations. Discrimination results are incorporated into fitting strategies for filters and compression in hearing aids.

The Speech Reception Threshold (SRT) is the lowest level at which 50% of a list of given words are correctly reproduced. It is measured in dB SPL or dB HL and correlates with hearing thresholds from tonal audiometry. Deviations between SRT and pitch threshold indicate speech comprehension problems or cognitive deficits. SRT is essential for setting the amplification in speech areas with hearing aids. Regular SRT checks document the success of the fitting.

Word identification measures the percentage of correctly recognized words in standardized tests at a fixed level or signal-to-noise ratio. It reflects functional speech comprehension and central processing ability. Results form the basis for fine-tuning hearing aids and assessing rehabilitation progress. Different word lists (single-syllable, multi-syllable) test different levels of complexity. Test repetitions in background noise quantify everyday performance.

Word spectral analysis breaks down speech signals into their frequency spectrum and shows formants, harmonics and noise components. It helps to identify phoneme-relevant frequency bands and adjust hearing aid filters accordingly. In research, spectral adjustments by hearing aids and their influence on speech comprehension are investigated. Software-supported spectral analysis visualizes real-time changes in speech production and perception. Results are incorporated into adaptive signal processing algorithms and speech coding techniques.