Acoustical noise or sound cancellation

Acoustic, nonairborne vibration sensing or counterwave emission

Adjacent ear

Counterwave generation control path

Adaptive filter topology

Algorithm or formula (e.g., lms, filtered-x, etc.)

Analog or nonadaptive

Nonacoustically derived reference signal

Tonal noise or particular frequency or band

From appliance

Particular transducer or enclosure structure

Within cabin or compartment of vehicle

Within duct

Artificial larynx, electrical

Audio transducer protection circuitry

Binaural and stereophonic

Binaural and stereophonic

Amplifier

Broadcast or multiplex stereo

Am or both am and angle final modulation

Having transmitter

Fm final modulation

Am subcarrier

Antinoise

Automatic switchover between mono and stereo modes

Channel separation control

Four discrete channels

Having transmitter

Having transmitter

Stereo indicators (e.g., stereo presence)

Switch-type detector or modulator

Four or more diodes

Two diodes

Center channel

Hearing aid

Pseudo stereophonic

Pseudo quadrasonic

Quadrasonic

Matrix

4-2-4

Variable decoder

With encoder

Stereo sound pickup device (microphone)

Stereo speaker arrangement

In furniture or clothing

In single baffle

In vehicle

Optimization

Enclosure adaptation

Enclosure orientation

Stereo earphone

Virtual positioning

Wireless or for use in diverse

Surround (i.e., front plus rear or side)

With image presentation means

Circuitry combined with specific type microphone or loudspeaker

With carbon microphone

With electrostatic loudspeaker

With electrostatic microphone

With magnetic loudspeaker

With magnetic microphone

With piezoelectric microphone

Dereverberators

Directive circuits for microphones

Electro-acoustic audio transducer

Body contact wave transfer (e.g., bone conduction earphone, larynx microphone)

By modifying fluid flow

Detail of mechanical vibration coupling to transducer (e.g., tuned vibrating element)

Driven diverse static structure (e.g., wall, sounding board)

Electromagnetic (e.g., dyynamic)

Basket detail

Conductive diaphragm (e.g., ribbon)

Cooling feature

Having diaphragm support feature

Including adjustment mechanism

Magnetic circuit

Armature diaphragm

Armature linked to diaphragm

Flux modifying means

Having central magnetic portion

Plural magnets

Like poles adjacent

Having damping

Inverted (e.g., within cone)

Magnetic liquid

Not having central magnetic portion

Movable voice coil

Centering from outside bobbin or diaphragm

Spider

Centering from within bobbin or diaphragm

Coil coating, winding layer structure, or wire

Field coil

Multiple voice coils

For different frequencies

Particular bobbin structure

Pattern

Wiring structure

Specified diaphragm shape or structure

Apertures in surface

Conical

Critically defined material or lamination

Fibrous

Metal

Dome or round

Flat

Plural portions or sections

Honeycomb

Electrostrictive, magnetostrictive, or piezoelectric

Having a fluid as a conducting element

Ionized gap, spark, or flame

Having acoustic wave modifying structure

Absorbing or attenuating element

Acoustic enclosure

Acoustic damping or attenuating resonator

Acoustic resistance

On front side of diaphragm

On rear side of diaphragm

Bass reflex (e.g., rear wave)

Front wave

Having internal wave reflecting means

Plural chambers

Reflecting element

Sound intensifying or spreading element

Horn

Inverted, folded, or curled

Phase plug

Plural horns or diaphragms

Mouthpiece

With tubular waveguide or resonant element

Having bi-directional transducer

Having body supported structure other than on head

Having electrostatic element (e.g., electret, vibrating plate)

Having protective or sheilding feature

Housed microphone

Cavity

Directional

With plural sound ports (e.g., pressure gradient)

Plural or variable characteristics

Mounting or support

Boom (other than on headset)

Detachable from support

In electronic apparatus or vehicle

In headgear

On body or clothing

On shock absorbing support

Stand or gooseneck

Windscreen

Microphone capsule only

Capacitive

Compound

Conductive diaphragm (e.g., reed, ribbon)

Dynamic (e.g., magnetic)

Light modifying

Micromagnetic

Piezoelectric or ferroelectric

Resistive

Granular or carbon

Differential

Semiconductor junction microphone

Vibrating electrical contract

Mounting or support feature of housed loudspeaker

Boom or support arm

Directional, directible, or movable

Electrical hardware

Electrical insulation feature

Grille

In vehicle

Mechanical detail

Resilient

With furniture, clothing, or image display

Plural or compound reproducers

Different types of diaphragms

Having common voice coil

Headphone

Electrical hardware feature

Particular cup

Having mechanical or acoustic sound attenuation

Openable to ambient

Particular support structure

Adjustable

And microphone

Collapsible

Ear insert or bone conduction

Headgear

Hook over ear or spectacle

Plural bands

Single band

Sound conducting tube

Plural diaphragms

Thermal response to, or generation of, sound vibration

With mechanical amplifier arrangement

Feedback suppression

Having microphone

Having non-electrical feature (e.g., mounting)

And loudspeaker

Curved or angled housing

Plural diaphragms, compartments, or housings

Portable or for use in diverse environment

With furniture, clothing, or image presentation means

Having microphone

Loudspeakers driven in given phase relationship

Headphone circuits

Hearing aids, electrical

Directional

Frequency transposition

Noise compensation circuit

Feedback suppression

Programming interface circuitry

Remote control, wireless, or alarm

Specified casing or housing

Cerumen protection

Component mounting

Ear insert

Device for manipulation

Hook over ear

Inductive pickup

Non-air-conducted sound delivery

Power supply or programming interface terminals

Spectacle

Spectral control

Wideband gain control

With vacuum tube amplifier

Hearing protectors, electrical

Helium speech

Including amplitude or volume control

Automatic

Including feedback

Remote

With amplitude compression/expansion

With manual volume control

Including frequency control

Automatic tone control

With amplitude control

Having automatic equalizer circuit

Having crossover filter

With active device

Including phase control

Lecterns

Loudspeaker feedback

Megaphones

Microphone feedback

Miscellaneous

Monitoring of sound

Amplification control responsive to ambient sound

Monitoring/measuring of audio devices

Loudspeaker operation

Testing of hearing aids

Noise or distortion suppression

Feedforward circuitry for transducer compensation

Hum or ground loop

Interpolation

Peak limiting or pulsive noise compensation

Soft switching, muting, or noise gating

Spectral adjustment

In multiple frequency bands

Using signal channel and noise channel

One-way audio signal program distribution

Drive-in

Multiple channel

With switching

Near field

Public address system

Feedback suppression

Spare amplifier substitution

Speaker or channel switching

Sound effects

Reverberators

Mechanical (e.g., reverberation chamber)

Helical spring

Tremelo or vibrato effects

Sound or noise masking

Stethoscopes, electrical

Switching

Vehicle

Voice controlled

With amplifier

Feedback

With mixer

With musical instrument