Conversely, a thick, smooth painted concrete ceiling would be the acoustic equivalent of a mirror, and would have an absorption coefficient very close to 0.

Air pressure from an acoustic phone altered the flame provided by a Bunsen gas flame, which was amplified by a rotating mirror and recorded

* Lloyd's mirror, an optical and an acoustic experiment

4. 5 metre high WW1 concrete acoustic mirror near Kilnsea Grange, East Yorkshire, UK.

An acoustic mirror is a passive device used to reflect and perhaps to focus ( concentrate ) sound waves.

The acoustic mirror programme, led by Dr William Sansome Tucker, had given Britain the methodology to use interconnected stations to pin point the position of an enemy in the sky.

Parabolic microphones appear to use acoustic mirror properties but instead depend on a parabolic dish to reflect sound coming from a specific direction into the microphone placed at the focus.

# REDIRECT acoustic mirror

The design is close to that of an acoustic mirror in Kilnsea, East Riding of Yorkshire.

The acoustic equations for the conservation of momentum and the conservation of mass are often expressed in time harmonic form ( at fixed frequency ).

The one occasion where the band was introduced as " The Alan Parsons Project " in a live performance was at Night of the Proms 1990 ( at the time of the group's break-up ), featuring all Project regulars except Woolfson who was present but behind the scenes, while Parsons stayed at the mixer except during the last song, where he played acoustic guitar.

Featuring philosophical post-hippie lyrics on peace, love and morality, its acoustic folk rock occasionally fortified by harder rock, the album was not a commercial success at the time of its release.

At the receiving end, a handset ’ s speaker was attached to an acoustic coupler ( a microphone ), and a demodulator converted the varying tone into a variable current that controlled the mechanical movement of a pen or pencil to reproduce the image on a blank sheet of paper on an identical drum rotating at the same rate.

The saddle's basic purpose is to provide the end point for the string's vibration at the correct location for proper intonation, and on acoustic guitars to transfer the vibrations through the bridge into the top wood of the guitar.

Some acoustic and classical guitars only have a single strap button at the bottom of the body — the other end must be tied onto the headstock, above the nut and below the machine heads.

Some acoustic and classical guitars come with no strap buttons at all.

They dedicated an acoustic version of Duke Ellington's " Jump for Joy " to him, a song they never performed at any other time of their career.

When the " Salvador Ibáñez " workshop was destroyed during the Spanish Civil War, the " Ibanez Salvador " guitars were no longer available, so Hoshino Gakki bought the " Ibanez Salvador " brand name rights and started making Spanish acoustic guitars in 1935, at first using the " Ibanez Salvador " brand name, and then later using the " Ibanez " brand name.

.. the entire album, anchored by Latin-styled acoustic guitar trums and the velvety vocals of Lee and guitarist Bryan Maclean, is remarkably consistent at a lofty level.

The device was fixed underwater at Temple Pier in Urquhart Bay and directed towards the opposite shore, effectively drawing an acoustic ' net ' across the width of Ness through which no moving object could pass undetected.

The album's rich acoustic sound initially received mixed reactions, with critics and fans surprised at the turn from the primarily electric arrangements of the first two albums, fuelling further hostility to the musical press.

Drug use and attempts at psychedelic music moved out of acoustic folk-based music towards rock soon after The Byrds " plugged in " to produce a chart topping version of Dylan's Mr. Tambourine Man in the summer of 1965, which became a folk rock standard.

In 2010, Robyn guest-starred in " War at the Roses ", an episode which was on Gossip Girl, where she performed the acoustic version of " Hang With Me ".

and its first three singles, two more singles were released in the second half of 2003 with up-tempo " Thank You Baby " (# 11 in the UK, Top 20 in Germany ) and just before Christmas the romantic, acoustic ballad " When You Kiss Me ", at least a minor hit in both territories.

The band's appearance at Reading Festival during the 2003 tour had another impromptu acoustic set, this time due to equipment failure.

A somewhat different implementation was demonstrated at Pennsylvania State University using a microchip which generated a pair of perpendicular standing surface acoustic waves allowing to position particles equidistant to each other on a grid.

The parts of a violin are usually made from different types of wood ( although electric violins may not be made of wood at all, since their sound may not be dependent on specific acoustic characteristics of the instrument's construction ), and it is usually strung with gut, nylon or other synthetic, or steel strings.

He began studying piano at the age of nine, showing an aptitude for music by learning to play several different instruments, including the banjo and acoustic and bass guitars.

Albanian drivers are prone to using visual and acoustic aids regularly such as honking, headlight flashing, or high beams at night.

Like mechanical resonance, acoustic resonance can result in catastrophic failure of the object at resonance.

It is for this reason that the ultra low frequency band of the electromagnetic spectrum between 300 and 3000 Hz is also referred to as voice frequency, being the electromagnetic energy that represents acoustic energy at baseband.

In the March 8, 2002 issue of the peer-reviewed journal Science, Rusi P. Taleyarkhan and colleagues at the Oak Ridge National Laboratory ( ORNL ) reported that acoustic cavitation experiments conducted with deuterated acetone () showed measurements of tritium and neutron output that were consistent with the occurrence of fusion.

* Dungeness acoustic mirrors

The word " acoustic " is derived from the Greek word ακουστικός ( akoustikos ), meaning " of or for hearing, ready to hear " and that from ἀκουστός ( akoustos ), " heard, audible ", which in turn derives from the verb ἀκούω ( akouo ), " I hear ".

Physicists and acoustic engineers tend to discuss sound pressure levels in terms of frequencies, partly because this is how our ears interpret sound.

The Spectrogram produced by such an instrument is a graphical display of the time varying pressure level and frequency profiles which give a specific acoustic signal its defining character.

where is the acoustic pressure and is the acoustic fluid velocity vector, is the vector of spatial coordinates, is the time, is the static mass density of the medium and is the bulk modulus of the medium.

The acoustic wave equation is a combination of these two sets of balance equations and can be expressed as

In that case the acoustic wave equation is written as

An important simplifying assumption for acoustic waves is that the amplitude of the disturbance of the field quantities is small.

To do that we assume that the medium is an ideal gas and all acoustic waves compress the medium in an adiabatic and reversible manner.

The value of is 1. 4 if the acoustic medium is air.

Then the solution of the acoustic wave equation is

The steel-string acoustic guitar is a modern form of guitar that descends from the classical guitar, but is strung with steel strings for a brighter, louder sound.