Glossary of Vibroacoustic Therapy Device Related Terms & Specifications

Amplifier

An electronic device that increases the power of an audio signal to drive speakers or transducers. In vibroacoustic systems, the amplifier determines how much power is delivered to the tactile transducers, directly affecting vibration intensity. Professional-grade amplifiers like the Crown XLS series offer higher power output, lower distortion, and greater reliability than consumer-grade alternatives.

Example: The Crown XLS 1502 delivers 600 watts RMS, while most competitor systems use 100-300 watt amplifiers.

Audible Sound

Sound frequencies within the range of human hearing, theoretically spanning 20Hz to 20kHz, though actual perception varies significantly by individual and age. The lower end of this range (20-80Hz) is perceived as deep bass rumble, often felt as much as heard. Mid frequencies (250Hz-4kHz) contain most speech and musical detail. Higher frequencies (4kHz-20kHz) provide brightness, air, and spatial cues. Age significantly impacts audible range, particularly at the high end. Most adults begin losing sensitivity above 15kHz by their 30s, with this ceiling dropping progressively. By age 50, many people cannot hear frequencies above 12kHz. Low frequency perception remains relatively stable with age. In vibroacoustic therapy, audible sound delivered through headphones works in conjunction with tactile sound (vibrations felt through the body) to create a complete multisensory experience. The two pathways complement each other: you hear the music while simultaneously feeling its lower frequencies transmitted through the transducers. This dual-pathway approach engages both auditory and somatosensory processing, creating immersion that neither modality achieves alone.

Example: A 25-year-old may hear frequencies up to 17kHz while a 55-year-old perceives the same content with an effective ceiling around 10-12kHz. Both feel the same tactile frequencies through a vibroacoustic bed.

Audio Channels

The number of independent audio signals an amplifier can process simultaneously. A 2-channel (stereo) amplifier can send different signals to different transducer groups, enabling more nuanced vibration patterns. Single-channel (mono) systems send the same signal to all transducers.

Example: A 2-channel system can deliver different frequencies to upper and lower body transducers simultaneously.

Aux Input (Auxiliary Input)

An (i.e. 3.5mm, XLR, TRS) audio jack that allows direct wired connection from external audio sources such as smartphones, tablets, or computers. Provides a reliable, interference-free audio connection without the potential quality loss of wireless transmission.

Bass Shaker

A low-cost type of tactile transducer typically designed for home theater or gaming applications. Bass shakers generally have limited frequency response (often 20-80Hz), use mechanical suspension systems, and produce less precise vibrations compared to professional-grade tactile transducers. They are adequate for rumble effects but lack the fidelity required for therapeutic applications.

Example: The Dayton Audio BST-1 is a common bass shaker used in budget vibroacoustic systems.

Binaural Beats

An auditory phenomenon that occurs when two slightly different frequencies are presented separately to each ear through headphones. The brain perceives a third tone, the "binaural beat," at the mathematical difference between the two frequencies. For example, if 200Hz is played in one ear and 210Hz in the other, the brain perceives a 10Hz binaural beat. This perceived frequency can influence brainwave activity through entrainment, guiding the brain toward corresponding states. Binaural beats in the delta range (1-4Hz) promote deep sleep, theta (4-8Hz) supports meditation and creativity, alpha (8-12Hz) encourages relaxation, and beta (12-30Hz) enhances focus and alertness. Stereo headphones are required for binaural beats to work since each ear must receive a distinct frequency. Binaural beats can be combined with vibroacoustic therapy for enhanced entrainment effects.

Example: A meditation track using 100Hz in the left ear and 106Hz in the right creates a 6Hz theta binaural beat to support deep meditative states.

Bioacoustics

The scientific study of sound production, transmission, and reception in living organisms. In the context of vibroacoustic therapy, bioacoustics encompasses how sound frequencies interact with biological tissues, how the body perceives and responds to vibration, and how acoustic energy can influence physiological processes. Bioacoustic research informs the development of therapeutic protocols by identifying which frequencies, amplitudes, and durations produce beneficial effects on specific body systems. The field bridges biology, physics, and acoustics to understand phenomena ranging from how cells respond to mechanical vibration to how the nervous system processes tactile sound information.

Bluetooth

A wireless technology for transmitting audio over short distances. While convenient, standard Bluetooth compresses audio data, which can reduce sound quality. Bluetooth 5.0 offers improved range and stability over earlier versions. For highest audio fidelity, Wi-Fi streaming protocols like AirPlay 2 or wired connections are preferred.

Body Transducer

Another term for a tactile transducer. See Tactile Transducer.

Brainwave Entrainment

The process by which external rhythmic stimuli influence the brain's electrical activity, guiding brainwaves toward synchronization with the stimulus frequency. This phenomenon, also called the frequency following response, occurs because neurons naturally tend to align their firing patterns with consistent external rhythms. Entrainment can be induced through auditory stimuli (binaural beats, isochronic tones, rhythmic music), visual stimuli (stroboscopic or flickering light), or tactile stimuli (vibroacoustic vibration). The brain operates at different frequency bands associated with different states of consciousness: delta (0.5-4Hz) for deep sleep, theta (4-8Hz) for meditation and dreams, alpha (8-12Hz) for relaxed awareness, beta (12-30Hz) for active thinking, and gamma (30Hz+) for peak performance and insight. By exposing the brain to stimuli at these target frequencies, entrainment technologies can help guide consciousness toward desired states more reliably than unassisted practice.

Example: A 10Hz flickering light entrains brainwaves toward alpha frequency, promoting a state of relaxed, calm awareness.

Closed Ecosystem

A system that restricts users to proprietary content and apps, preventing the use of third-party audio sources or streaming services. Closed ecosystems limit flexibility and create dependency on the manufacturer's continued software support.

Example: A system that only plays content from its own app and doesn't allow Spotify, Apple Music, or personal audio files.

Continuous Power (RMS)

See RMS Power.

Crossover

An electronic filter that divides an audio signal into separate frequency bands, directing specific frequencies to appropriate transducers or speakers. In vibroacoustic systems, a crossover determines which frequencies are sent to the tactile transducers versus headphones. Adjustable crossovers allow users to customize the frequency split point for different content types.

Example: A crossover set at 200Hz sends frequencies below 200Hz to the transducers and frequencies above 200Hz to the headphones.

Cyberdelic

A fusion of "cyber" and "psychedelic," referring to technology-assisted experiences that induce altered states of consciousness without the use of substances. Cyberdelic technologies use external stimuli such as stroboscopic light, vibroacoustic vibration, binaural beats, and sensory modulation to guide the brain into specific states naturally. The term encompasses both the technologies themselves and the experiences they produce, which can range from deep relaxation and enhanced meditation to vivid visual journeys that users compare to traditional psychedelic experiences. Unlike substance-induced states, cyberdelic experiences offer complete user control and can be stopped instantly. The combination of vibroacoustic therapy with stroboscopic light entrainment represents one of the most powerful cyberdelic stacks available, addressing both somatic and visual-cognitive dimensions of consciousness simultaneously.

Example: A session combining the Zenthesia Sound Therapy Bed with the roXiva RX1 stroboscopic light creates a full cyberdelic experience through synchronized vibration, sound, and light.

Cymatics

The study of visible sound vibration patterns, typically demonstrated by observing how sound frequencies cause particles (such as sand, water, or powder) to form geometric patterns on a vibrating surface. Cymatics visually illustrates that different frequencies create distinct, organized patterns. Higher frequencies produce more complex geometries with smaller wavelengths, while lower frequencies create simpler, larger patterns. In vibroacoustic therapy contexts, cymatics is often referenced to conceptualize how sound frequencies might interact with the body's tissues and fluids. While cymatics demonstrates the organizing properties of sound in physical media, its direct therapeutic applications remain an area of ongoing exploration rather than established science.

Example: Sand on a metal plate forms a star pattern at one frequency and shifts to a different geometric pattern when the frequency changes.

dB (Decibel)

A logarithmic unit used to measure sound intensity, signal strength, or noise reduction. In audio specifications, decibels quantify signal-to-noise ratio (SNR) and passive noise isolation. Higher dB values for SNR indicate cleaner audio; higher dB values for noise isolation indicate better blocking of external sound.

Example: Headphones with 32dB passive isolation reduce ambient noise to less than 10% of perceived loudness.

Distortion

Any unwanted alteration of an audio signal that causes the output to differ from the input. In vibroacoustic systems, distortion can manifest as buzzing, rattling, or muddy vibrations that obscure the intended audio content. Distortion typically occurs when amplifiers are pushed beyond their rated capacity, when transducers receive frequencies outside their optimal range, or when low-quality components cannot accurately reproduce the signal. Total Harmonic Distortion (THD) measures this degradation as a percentage. Lower values indicate cleaner reproduction. Professional-grade amplifiers maintain THD below 0.5%, while audiophile headphone amplifiers can achieve THD below 0.01%. High distortion not only reduces audio fidelity but can also diminish the therapeutic effectiveness of vibroacoustic sessions by introducing incoherent vibrations that conflict with the intended frequencies.

Example: An amplifier with 1% THD produces noticeably more coloration than one with 0.5% THD, potentially affecting both sound quality and vibration clarity.

DLNA (Digital Living Network Alliance)

A networking standard that allows media devices to share content over a local network. DLNA-compatible vibroacoustic systems can stream audio from computers, NAS drives, or other networked devices without compression losses associated with Bluetooth.

Driver (Headphone)

The component inside headphones that converts electrical signals into sound. Driver size, measured in millimeters (mm), affects frequency response and sound characteristics. Larger drivers (40-50mm) generally produce fuller bass response, though driver quality matters more than size alone.

Flat Response Curve

An audio reproduction characteristic where all frequencies are reproduced at equal intensity without artificial boosting or cutting. Flat/neutral response curves are preferred for therapeutic applications because they deliver audio content exactly as it was designed, without coloration. Consumer headphones often use "V-shaped" curves that boost bass and treble while recessing midrange frequencies.

Example: The Sennheiser HD 280 PRO has a flat response curve ideal for accurate audio reproduction.

Frequency Generator

A device or software application that produces audio signals at specific, user-defined frequencies. Frequency generators allow practitioners to create precise tones for targeted therapeutic applications rather than relying solely on pre-recorded music or content. They can output single frequencies (pure tones), frequency sweeps (gradually changing pitch), or combinations of frequencies. In vibroacoustic therapy, frequency generators enable customized protocols targeting specific therapeutic goals, though most users rely on professionally designed content that incorporates appropriate frequencies within musical compositions for a more pleasant experience.

Example: A frequency generator set to 40Hz produces a continuous low tone that can be felt as steady vibration through a vibroacoustic bed.

Frequency Response

The range of frequencies a device can reproduce, measured in Hertz (Hz). For tactile transducers, a wider frequency response means more therapeutic content can be accurately delivered. Human hearing ranges from approximately 20Hz to 20kHz; tactile sensation extends below 20Hz into the infrasonic range.

Example: A transducer with 10Hz-800Hz response can reproduce deeper infrasonic frequencies than one limited to 20Hz-80Hz.

Full-Spectrum (Tactile)

A vibroacoustic system capable of reproducing the complete range of tactile frequencies humans can perceive, typically from infrasonic frequencies below 20Hz up to approximately 800Hz. Full-spectrum systems deliver a more complete therapeutic experience by addressing different body areas and tissue depths simultaneously. Deep infrasonic vibrations stimulate the core and organs, mid-range frequencies address muscles and joints, and higher tactile frequencies create skin-surface sensation. Systems with limited frequency response (such as those restricted to 20-80Hz) can only deliver a fraction of the full tactile experience.

Example: A full-spectrum system with 10Hz-800Hz response versus a bass-shaker system limited to 20-80Hz.

Harmonic Resonance

The phenomenon where an object or system vibrates with increased amplitude when exposed to frequencies that match or harmonically relate to its natural resonant frequency. In the context of the human body, harmonic resonance refers to the theory that different tissues, organs, and body systems have characteristic frequencies at which they naturally vibrate, and that exposure to these frequencies through vibroacoustic therapy may support optimal function. While every physical structure has resonant properties, the therapeutic application of harmonic resonance to the body remains an area of active exploration. Proponents suggest that specific frequencies can "resonate" with corresponding body areas to promote relaxation, circulation, or cellular activity, though scientific validation of specific frequency-to-organ relationships continues to develop.

Example: A tuning fork vibrates more intensely when another fork of the same frequency is struck nearby, a demonstration of resonance that some practitioners conceptually apply to body-frequency relationships.

Harmonics

Frequencies that are whole number multiples of a fundamental frequency. When a note is played at 100Hz (the fundamental), harmonics occur at 200Hz (2nd harmonic), 300Hz (3rd harmonic), 400Hz (4th harmonic), and so on. Harmonics are what give instruments and sounds their unique character or timbre. A piano and a guitar playing the same note sound different because of their distinct harmonic content. In vibroacoustic therapy, harmonics are significant because playing a low fundamental frequency simultaneously generates higher frequency content that extends the tactile experience across a broader range of the body. A 40Hz tone rich in harmonics will produce vibrations not only at 40Hz but also at 80Hz, 120Hz, 160Hz, and beyond. This creates a fuller, more complex sensation compared to a pure sine wave at a single frequency. Systems with wider frequency response can reproduce more of these harmonics, contributing to a richer and more immersive vibroacoustic experience.

Example: A cello playing a 100Hz note produces harmonics at 200Hz, 300Hz, 400Hz, and higher, all of which contribute to the instrument's warm, rich tone and create layered tactile sensations when played through a vibroacoustic system.

Headphone Amplifier

A dedicated amplifier designed specifically to drive headphones. Separate headphone amplifiers typically offer superior audio quality compared to integrated amplifier circuits, with lower distortion, higher signal-to-noise ratios, and sufficient power to drive high-impedance audiophile headphones.

Example: The JDS Labs Atom AMP 2 delivers THD below 0.01% and SNR of 124dB.

Hertz (Hz)

The unit of frequency measurement representing one cycle per second. Audio frequencies are measured in Hz and kilohertz (kHz, equal to 1,000 Hz). Lower Hz values represent deeper bass frequencies; higher values represent treble frequencies. Infrasonic frequencies below 20Hz can be felt but not heard.

Example: 10Hz is an extremely low frequency felt as deep vibration; 10kHz is a high-pitched tone.

High-Fidelity (Hi-Fi)

Audio reproduction that accurately represents the original recording with minimal distortion or coloration. High-fidelity components prioritize accuracy over artificially enhanced sound characteristics.

High-Resolution Audio (Hi-Res Audio)

Audio that exceeds the quality of standard CD audio (16-bit/44.1kHz), typically defined as 24-bit depth and sample rates of 48kHz or higher (commonly 96kHz or 192kHz). Higher bit depth captures more dynamic range and subtle volume gradations, while higher sample rates preserve more detail in high frequencies. In vibroacoustic applications, high-resolution audio offers greater precision in the low-frequency content that drives tactile transducers, potentially delivering smoother, more nuanced vibrations compared to compressed formats like MP3 or standard Bluetooth audio. To benefit from hi-res audio, the entire signal chain must support it, from the source file through the streaming protocol, amplifier, and transducers. Wi-Fi streaming via AirPlay 2, Tidal Connect, or DLNA can transmit high-resolution audio, while standard Bluetooth cannot.

Example: A 24-bit/96kHz audio file contains significantly more data than a 16-bit/44.1kHz CD or a 320kbps MP3, preserving subtle details that may enhance the vibroacoustic experience.

Impedance (Ω)

Electrical resistance measured in ohms (Ω). In audio systems, impedance matching between amplifiers and transducers/headphones is important for optimal power transfer and sound quality. Mismatched impedance can result in reduced output or potential equipment damage.

Example: An amplifier rated at "300W @ 8Ω" delivers 300 watts when connected to 8-ohm transducers.

Infrasonic

Frequencies below the threshold of human hearing (approximately 20Hz). Infrasonic vibrations can be felt physically even though they cannot be heard. Some vibroacoustic therapy protocols specifically target infrasonic frequencies for deep tissue stimulation.

Example: A transducer capable of 10Hz output can deliver infrasonic frequencies.

Isochronic Tones

Rhythmic audio pulses of a single tone that turn on and off at precise intervals to create brainwave entrainment effects. Unlike binaural beats, which require headphones and present different frequencies to each ear, isochronic tones work through speakers or headphones because the entrainment comes from the rhythmic pulsing itself rather than frequency interference between ears. The sharp, distinct pulses of isochronic tones create a stronger cortical response than the smooth, continuous wave of binaural beats, making them potentially more effective for entrainment. The pulse rate determines the target brainwave frequency. A tone pulsing 10 times per second (10Hz) encourages alpha brainwave activity. Isochronic tones are often layered beneath music or ambient soundscapes in therapeutic audio content.

Example: An isochronic tone pulsing at 4Hz embedded in ambient music supports theta brainwave states for deep meditation.

Linear Response

The ability of a transducer or amplifier to reproduce all frequencies within its range at consistent, proportional levels without favoring or attenuating specific frequency bands. Linear response is essential for accurate reproduction of therapeutic audio content, ensuring that the vibrations you feel match what the content creator intended. Non-linear components may artificially boost or cut certain frequencies, altering the therapeutic properties of the content. Reactive suspension transducers typically offer more linear response than mechanical suspension designs.

Lossless Audio

Audio formats or streaming protocols that preserve full audio quality without compression artifacts. Wi-Fi streaming via AirPlay 2, Spotify Connect (Premium), and Tidal Connect can deliver lossless audio, while standard Bluetooth compresses audio data.

Low Pass Filter

A type of crossover that allows frequencies below a set point to pass through while blocking higher frequencies. In vibroacoustic systems, low pass filters ensure only appropriate bass frequencies reach the tactile transducers.

Example: A 200Hz low pass filter sends only frequencies below 200Hz to the transducers.

Max Wattage

See Peak Power.

Mechanical Suspension

A transducer suspension system using a physical "spider" or surround to center and control the moving mass. Mechanical suspensions are common in standard speakers and bass shakers but can introduce resonance peaks and non-linear movement at certain frequencies, reducing accuracy.

Milliwatt (mW)

One-thousandth of a watt, used to measure headphone amplifier output power. Headphone power requirements vary by impedance; high-impedance audiophile headphones may require several hundred milliwatts for optimal performance.

Example: An amplifier delivering 286mW at 300Ω can adequately drive most high-impedance headphones.

Muddy Sound

An audio quality issue where frequencies blend together indistinctly, resulting in a lack of clarity, definition, and separation between different elements of the sound. In vibroacoustic systems, muddy sound typically results from low-quality transducers, insufficient power, resonant peaks that emphasize certain frequencies while masking others, or frequency response limitations that compress the tactile spectrum into a narrow band. Muddy vibrations feel imprecise and boomy rather than clean and articulate. The sensation is similar to the difference between hearing music through a high-quality speaker versus a cheap, distorted one. For therapeutic applications, muddy sound reduces the coherence of the vibroacoustic experience and can diminish its effectiveness. High-fidelity systems with adequate power, reactive suspension transducers, and wide frequency response deliver clean, precise vibrations where individual frequencies remain distinct.

Example: A bass shaker limited to 20-80Hz with a resonant peak at 50Hz produces muddy, boomy vibrations, while a full-spectrum transducer delivers clean, articulate tactile sound across the entire frequency range.

Music Therapy

A clinical and evidence-based practice that uses music interventions to accomplish individualized therapeutic goals within a therapeutic relationship. Music therapy is conducted by credentialed professionals (board-certified music therapists) who assess client needs, create treatment plans, and use techniques such as songwriting, improvisation, lyric analysis, and receptive listening. While related to sound therapy, music therapy specifically involves the intentional use of music's elements (rhythm, melody, harmony) and the therapeutic relationship, rather than focusing primarily on frequency-based physiological effects. Vibroacoustic therapy can be incorporated as one tool within music therapy practice, but the two terms are not interchangeable. Music therapy is a broader clinical discipline with established credentials and protocols.

Example: A music therapist might use vibroacoustic equipment as part of a session focused on anxiety reduction, combining tactile vibration with guided musical experiences.

Nervous System Regulation

The process of shifting the autonomic nervous system between sympathetic ("fight or flight") and parasympathetic ("rest and digest") states. Vibroacoustic therapy is believed to support nervous system regulation by using specific low-frequency vibrations to activate the parasympathetic response, promoting relaxation, reduced heart rate, lower blood pressure, and decreased stress hormones. The combination of tactile vibration and synchronized audio creates multisensory stimulation that can help interrupt stress patterns and guide the body toward a calmer physiological state.

Noise Floor

The baseline level of unwanted electrical noise present in an audio system when no signal is playing. A lower noise floor means quieter silent passages and greater dynamic range. The noise floor is directly related to Signal-to-Noise Ratio (SNR). Higher SNR values indicate a lower, less audible noise floor. In vibroacoustic systems, a high noise floor can manifest as constant low-level hum or hiss through headphones and potentially unwanted subtle vibrations through transducers.

Example: An amplifier with 124dB SNR has an essentially inaudible noise floor, while one with 85dB SNR may have noticeable background hiss.

Ohm (Ω)

See Impedance.

Open Platform

A system that allows users to play audio from any source, including streaming services, personal music libraries, and third-party apps. Open platforms provide flexibility and are not dependent on a single manufacturer's content ecosystem.

Passive Noise Isolation

Sound blocking achieved through physical materials and design rather than electronic noise cancellation. Over-ear headphones with good passive isolation (25-32dB) create a seal around the ears that blocks ambient sound, enhancing immersion during vibroacoustic sessions.

Example: 32dB passive isolation reduces ambient noise to less than 10% of perceived loudness.

Peak Power

The maximum instantaneous power an amplifier or transducer can handle for brief moments, sometimes also referred to as "max wattage." Peak power ratings are significantly higher than continuous (RMS) ratings and can be misleading when comparing equipment. Manufacturers sometimes emphasize peak power in marketing because it produces larger, more impressive numbers. Always compare RMS ratings for accurate assessment of real-world performance.

Example: A transducer rated at "100W peak" may only handle 50W continuous (RMS).

Power Handling

The amount of electrical power a transducer can receive without damage, measured in watts. Higher power handling allows for more intense vibrations. Transducer power handling should match or exceed the amplifier's output to prevent damage.

Reactive Suspension

An advanced transducer suspension technology that provides precise, linear movement across the frequency spectrum without the resonance peaks associated with mechanical suspensions. Reactive suspension transducers deliver cleaner, more accurate vibrations for high-fidelity tactile reproduction.

Example: The HFT-150 transducers use reactive suspension technology manufactured in Sheffield, England.

Rehabilitation Acoustics

The application of sound and vibration technologies within physical rehabilitation and therapeutic recovery settings. Rehabilitation acoustics encompasses the use of vibroacoustic therapy, music therapy, and other sound-based interventions to support recovery from injury, surgery, neurological conditions, or chronic pain. In clinical rehabilitation contexts, acoustic interventions may be used to reduce muscle tension, improve range of motion, decrease pain perception, support neuroplasticity, and enhance patient relaxation during therapy sessions. The field integrates principles from physical therapy, occupational therapy, and acoustic science to optimize recovery outcomes through controlled application of sound and vibration.

Example: A physical therapy clinic using vibroacoustic beds to help patients relax muscles before manual therapy or to support recovery between exercise sets.

Resonant Peaks

Frequencies at which a transducer or enclosure vibrates with exaggerated intensity due to physical resonance characteristics, causing certain frequencies to be unnaturally louder or more pronounced than others. Resonant peaks are a common problem with mechanical suspension transducers and poorly designed enclosures, resulting in uneven, boomy, or muddy vibration output. These peaks can mask subtle frequencies and create an inaccurate representation of the audio content. High-quality transducers with reactive suspension technology minimize resonant peaks for smoother, more accurate frequency response across the entire tactile spectrum.

Example: A bass shaker with a resonant peak at 50Hz will produce exaggerated vibration at that frequency while underperforming at neighboring frequencies, creating an unbalanced sensation.

Response Curve

A graphical representation of how a device reproduces different frequencies. A "flat" curve reproduces all frequencies equally; a "V-shaped" curve boosts bass and treble while reducing midrange. For therapeutic applications, flat response curves are preferred for accuracy.

RMS Power (Root Mean Square)

A measurement of continuous power output that an amplifier can sustain or a transducer can handle indefinitely without damage. RMS is the most accurate way to compare amplifier and transducer power ratings. Always use RMS values rather than peak power for equipment comparisons.

Example: 600W RMS means the amplifier can continuously deliver 600 watts of power.

Sensory Integration Therapy

A therapeutic approach, primarily used in occupational therapy, that helps individuals process and respond to sensory information from their environment and body. Sensory integration therapy addresses difficulties with how the brain receives, organizes, and interprets input from the senses, including touch, movement, body awareness, sight, sound, smell, and taste. Vibroacoustic therapy can serve as one component of sensory integration work, providing controlled tactile and auditory input that helps regulate the nervous system. This application is particularly relevant for individuals with sensory processing disorders, autism spectrum conditions, ADHD, anxiety disorders, or trauma-related sensory sensitivities. The predictable, controllable nature of vibroacoustic stimulation makes it useful for gradually introducing sensory input in therapeutic contexts.

Example: An occupational therapist using a vibroacoustic surface to provide calming, organized sensory input for a child who is overwhelmed by unpredictable environmental stimuli.

Signal-to-Noise Ratio (SNR)

The ratio between the desired audio signal and background noise, measured in decibels (dB). Higher SNR values indicate cleaner audio with less audible hiss or interference. Professional audio equipment typically achieves SNR above 100dB; consumer equipment may fall below 90dB.

Example: An amplifier with 124dB SNR produces virtually no audible noise.

Solfeggio Frequencies

A set of specific frequencies (174Hz, 285Hz, 396Hz, 417Hz, 528Hz, 639Hz, 741Hz, 852Hz, 963Hz) associated with various therapeutic and meditative traditions. Vibroacoustic systems with wider frequency response can reproduce more of these frequencies as tactile vibrations.

Sound Therapy

A broad category of therapeutic practices that use sound, music, and vibration to promote physical, emotional, and mental well-being. Sound therapy encompasses many modalities including vibroacoustic therapy, sound baths, tuning fork therapy, binaural beats, gong therapy, singing bowl sessions, and guided audio meditations. Unlike music therapy (which requires credentialed practitioners and focuses on therapeutic relationships), sound therapy generally refers to the direct physiological and psychological effects of acoustic stimulation. Vibroacoustic therapy is a specific subset of sound therapy distinguished by its delivery of frequencies through physical contact with transducer-equipped surfaces, creating both auditory and tactile experiences simultaneously.

Example: Vibroacoustic beds, sound baths with singing bowls, and binaural beat recordings are all forms of sound therapy.

Spatial Audio

Audio technology that creates a three-dimensional sound experience, with sounds appearing to come from different positions around the listener. Some vibroacoustic systems use multiple transducer zones to create spatial vibration effects across the body.

Spotify Connect

A Wi-Fi streaming protocol that allows Spotify to stream directly to compatible devices without using Bluetooth. Spotify Connect can deliver higher quality audio than Bluetooth and allows phone-free operation once streaming begins.

Tactile Sound

Vibrations that are felt physically through the body rather than heard audibly through the ears. Tactile sound is the foundation of vibroacoustic therapy, where audio frequencies are converted into physical vibrations transmitted through the body via direct contact with transducer-equipped surfaces. Humans can feel a broader range of frequencies than we can hear. While audible hearing typically ranges from 20Hz to 20kHz, tactile perception extends from approximately 1Hz to 800Hz, with the most sensitive range between 150Hz and 300Hz. Below 20Hz (infrasonic frequencies), vibrations cannot be heard but can still be deeply felt. These ultra-low frequencies create sensations of pressure and movement in the chest and abdomen. From 20Hz to 80Hz, vibrations are perceived as deep rumble in the torso and larger muscle groups. The 80Hz to 200Hz range is felt across broader body areas including the back, legs, and arms. Above 200Hz up to approximately 800Hz, tactile sensation becomes more localized and surface-level, perceived as buzzing or tingling on the skin. Different body parts have varying sensitivity to tactile frequencies. Fingertips are most sensitive (detecting vibrations up to 800Hz), while the torso responds best to lower frequencies (20-200Hz). This is why full-body vibroacoustic systems with wide frequency response can create more nuanced, full-spectrum therapeutic experiences compared to systems limited to narrow bass-only ranges.

Example: A system with 10Hz-800Hz response can deliver deep infrasonic vibrations felt in the core as well as higher tactile frequencies perceived across the skin's surface, creating a complete full-body experience.

Tactile Transducer

A device that converts audio signals into physical vibrations transmitted through solid materials. Unlike speakers that move air, tactile transducers are mounted to surfaces (beds, chairs, platforms) and transfer vibrations directly to the body through contact. Quality varies dramatically between budget bass shakers and professional high-fidelity transducers.

Example: The HFT-150 is a high-fidelity tactile transducer with 10Hz-800Hz frequency response and 150W power handling.

Third-Party Verified Reviews

Customer reviews collected and displayed through independent platforms (such as Judge.me, Trustpilot, or Google Reviews) that verify purchase authenticity. Third-party verification prevents manufacturers from filtering negative reviews or creating fake positive reviews.

Tidal Connect

A Wi-Fi streaming protocol from the Tidal music service that enables high-resolution lossless audio streaming directly to compatible devices. Tidal Connect can deliver master-quality audio superior to standard Bluetooth streaming.

Total Harmonic Distortion (THD)

A measurement of signal distortion introduced by audio equipment, expressed as a percentage. Lower THD values indicate cleaner, more accurate audio reproduction. Professional amplifiers achieve THD below 0.5%; audiophile-grade headphone amplifiers can achieve THD below 0.01%.

Example: THD of 0.01% means distortion is virtually inaudible; THD of 1% may produce noticeable coloration.

Transducer Matching

The practice of pairing amplifiers and transducers with compatible power and impedance specifications for optimal performance and safety. Proper matching ensures transducers receive adequate power to perform effectively without risk of damage from overpowering. An underpowered transducer produces weak, unsatisfying vibrations; an overpowered transducer may distort or fail prematurely. Ideally, amplifier output should match or slightly exceed transducer RMS power handling at the correct impedance rating.

Example: Four 150W transducers paired with a 600W amplifier represents proper matching, delivering full power without risk of damage.

Vibroacoustic

Relating to the combination of vibration and sound, particularly the delivery of audio frequencies through physical contact rather than through air. Vibroacoustic technology converts audio signals into mechanical vibrations transmitted directly through solid surfaces into the body. The term distinguishes this approach from conventional audio, which moves air to create sound waves perceived by the ears. Vibroacoustic devices include beds, tables, chairs, mats, and cushions equipped with tactile transducers. The vibroacoustic experience engages the somatosensory system (touch and body awareness) in addition to or instead of the auditory system, creating a fundamentally different relationship with sound where frequencies are felt throughout the body's tissues, muscles, and bones.

Vibroacoustic Music (VAM)

Music specifically composed or arranged for playback through vibroacoustic systems, designed to be both heard through headphones and felt through tactile transducers simultaneously. Unlike standard music that is mixed primarily for auditory experience, vibroacoustic music intentionally incorporates low-frequency content (typically below 200Hz) that translates effectively into physical vibration. Composers of VAM consider how bass frequencies, sub-bass tones, and rhythmic elements will feel in the body, not just how they sound to the ear. Well-designed vibroacoustic music creates coherence between the auditory and tactile experience. What you hear and what you feel work together to enhance relaxation, immersion, or therapeutic effect. VAM may include ambient soundscapes, meditation music, specially mastered versions of existing recordings, or compositions built around specific therapeutic frequencies. The effectiveness of VAM depends heavily on the playback system's frequency response; systems limited to narrow bass ranges cannot reproduce the full tactile spectrum intended by the composer.

Example: A vibroacoustic composition might feature a sustained 40Hz drone felt as deep vibration in the torso, layered with melodic elements heard through headphones, creating a unified multisensory experience.

Vibroacoustic Therapy (VAT)

A therapeutic modality that uses low-frequency sound vibrations transmitted directly through the body to promote physical and psychological well-being. Unlike conventional sound therapy that relies solely on auditory perception, vibroacoustic therapy delivers frequencies through direct physical contact with transducer-equipped surfaces such as beds, tables, chairs, or mats. The vibrations travel through the body's tissues, muscles, bones, and organs, creating a full-body sensory experience that research suggests can support relaxation, pain relief, stress reduction, and nervous system regulation.

Vibroacoustic therapy typically operates within the 20Hz to 200Hz range, though advanced systems extend from infrasonic frequencies below 20Hz up to 800Hz for full-spectrum tactile coverage. The therapy is often combined with synchronized audio through headphones, creating a dual-pathway experience where the body feels the vibrations while the ears hear complementary music or tones. This multisensory approach can enhance the depth of relaxation and therapeutic response beyond what either modality achieves alone.

VAT has been studied for applications including chronic pain management, fibromyalgia symptom relief, anxiety and stress reduction, improved circulation, muscle tension release, enhanced meditation depth, and support for individuals with neurological conditions. While not a replacement for medical treatment, vibroacoustic therapy is used as a complementary modality in wellness centers, spas, therapeutic practices, athletic recovery facilities, and private homes.

Example: A typical VAT session involves lying on a transducer-equipped bed for 20-60 minutes while therapeutic frequencies play through both the bed and headphones simultaneously.

Vibration Core

Another term for a tactile transducer. See Tactile Transducer.

V-Shaped Response Curve

A frequency response characteristic that boosts bass and treble frequencies while reducing midrange. Common in consumer and DJ headphones for a more "exciting" sound, but less accurate for therapeutic applications where flat response is preferred.

Watt (W)

The unit of electrical power. In audio systems, watts measure amplifier output power and transducer power handling capacity. Higher wattage generally enables more powerful vibrations, though efficiency and quality also matter significantly.

Weight Capacity

The maximum user weight a vibroacoustic bed or lounge can safely support. Important for commercial operators to know for liability purposes. Not all manufacturers publish weight capacity specifications.

Example: A bed rated for 450lbs can safely accommodate most users.

Wi-Fi Streaming

Audio transmission over a wireless network, typically offering higher quality than Bluetooth due to greater bandwidth. Wi-Fi streaming protocols include AirPlay 2, Spotify Connect, Tidal Connect, and DLNA. Wi-Fi streaming enables lossless audio transmission without compression artifacts.