These devices strengthen (boost) or weaken (cut) the energy of specific frequency bands or "frequency ranges". In sound recording and reproduction, equalization is the process commonly used to alter the frequency response of an audio system using linear filters.
Both gain and levels refer to the loudness of the audio. However, gain is the input level of the clips and volume is the output. In recording audio, gain is the first control that the microphone signal goes through in a mixer while levels are adjusted after that.
The purpose of an amplifier is to receive a small electrical signal and enlarge or amplify it. In the case of a pre-amplifier, the signal must be amplified enough to be accepted by a power amplifier.
An equaliser is a term used in Commonwealth English to describe a goal or run scored by one particular team that brings the scores level.
Topics: gain, Mixing Skills, technical By: Chris Huff. Gain, a.k.a. Trim, is a volume control for each channel of a mixing console. The Gain knob controls the volume being input into the channel, not the amount of volume output through the channel.
EQ is equalizer. Equalizers adjust the loudness of specific frequencies. For example, rap music sounds better with more low end (bass). You can choose what type of music you're listening to for a "better" sound for that music type.
The key to safe equalizing is opening the normally closed eustachian tubes, allowing higher-pressure air from your throat to enter your middle ears. Most divers are taught to equalize by pinching their nose and blowing gently. Called the Valsalva Maneuver, it essentially forces the tubes open with air pressure.
Equalizing Our Sinuses When We Freedive. When your sinuses are free from blockage or congestion, they will equalize at the same time as your ears, so we don't need to think about doing anything specific to equalize them.
The Frenzel Maneuver is named after Hermann Frenzel (German ear, nose and throat physician and Luftwaffe commander). The maneuver was developed in 1938 and originally was taught to dive bomber pilots during World War II. The maneuver is used to equalize pressure in the middle ear.
"Politzerization": a medical procedure that involves inflating the middle ear by blowing air up the nose during the act of swallowing; The "Toynbee maneuver": pinching the nose and swallowing.
However, you should avoid actively trying to pop your ears by pinching your nose or 'blowing open' your ears, as this may actually drive fluid up into the ears through the eustachian tubes and make things worse. Yawning, chewing gum, and gargling with warm salt water are all safe ways to 'pop' the ears.
The following may help return your fast heart rate to normal:
- Take a deep breath.
- Plug your nose and keep your mouth closed.
- Breathe out forcefully for about 10 to 15 seconds. You may feel your ears pop when doing this.
- When you do the VM lying down, have another person put a hand on your abdomen.
These simple maneuvers stimulate the vagus nerve, sometimes resulting in slowed conduction of electrical impulses through the atrioventricular (AV) node of the heart. Vagal maneuvers that you can try to slow your fast heart rate include: Gagging. Holding your breath and bearing down (Valsalva maneuver).
Hemodynamics of a Valsalva Maneuver. When a person forcefully expires against a closed glottis, changes occur in intrathoracic pressure that dramatically affect venous return, cardiac output, arterial pressure, and heart rate. This forced expiratory effort is called a Valsalva maneuver.
Maneuvers Changing Venous Return. Venous return to the heart decreases during the straining phase of the Valsalva maneuver and the squatting-to-standing maneuver. Venous return increases during passive leg elevation and the standing-to-squatting maneuver (see Table 43.3 for definitions).
A vagal maneuver is an action used to slow down the heart rate by stimulating the vagus nerve. Examples include: Czermak-Hering test. Oculocardiac reflex of Aschner-Dagnini. Valsalva maneuver.
Vagal Stimulation. This response is caused by stimulation of the right vagus nerve. After transmission excitation through parasympathetic ganglia ACh is released in the SA node of the heart. Thus, heart rate is slowed.
What is carotid sinus massage ? This is a procedure that is used to investigate unexplained dizziness, falls or faints. It involves gently massaging the carotid artery for 5 seconds on one side of your neck whilst monitoring your heart rhythm and blood pressure.
Carotid sinus massage is a simple bedside maneuver that helps to clarify the type and sometimes also the mechanism of different rhythm disturbances. The major indication for carotid sinus massage is the diagnosis of tachyarrhythmias in which the atrial activity is either absent or intermittently present.
Updated: 2nd October 2019