Volume
Volume is the loudness of the speaker. It is the psychological characteristic of physical strength (amplitude). It is perceived as auditory sensation by the listener which can be ordered on a scale from quiet to loud. Loudness is then a subjective measure of the listener, which is often confused with objective measures of sound strength such as sound pressure level (in decibels), sound intensity, or sound power. Amplitude is the strength or power of the wave signal. Higher amplitudes on the wave graph are interpreted as a higher volume, hence the name "amplifier" for a device that increases amplitude.
A sound wave with its frequency (pitch) and amplitude (loudness) labeled
Higher amplitude will be perceived as louder sound.
Using the "Naked" Speaking Voice
When speaking naturally without any amplification you need to keep in mind the distance to be covered by your voice. You might compare speaking with the act of throwing a ball. Consider how much more muscular effort is needed to throw the ball a long distance than is required to throw it a short one. As you speak, think of your words as balls and mentally watch them covering the space between you and your audience. Notice how you unconsciously lengthen the voice. If speaking in a face-to-face group without a microphone ask yourself if you are loud enough to be heard by audience members in the last row. Speaking to a large group will require more energy to breathe and control your sound production.
To become a better speaker with your "naked" speaking voice, try the following techniques:
- Practice speaking in a large room with a friend who moves farther and farther away from you until the friend reaches the rear of the room and can still hear you.
- Make sure that you are standing straight and not cramped so you have the maximum capacity for breathing and forcing air out of the lungs for sound production.
- Practice speaking by thinking of people at different distances to you such as at your elbow, across the room, or in the back of a large hall.
Using a microphone
In large rooms or when using videoconferencing equipment, you will use a microphone to convert sound into electrical signals for amplification. The signal may then be sent to an amplifier. The electronic amplifier increases the power of a signal. It does this by taking energy from a power supply and controlling the output to match the input signal shape but with a larger amplitude. A loudspeaker or headset receives the input to produce the amplified sound.
Sennheiser Microphone
Microphones are used by a speaker for large audiences, during recording or videoconferencing.
There are several different types of microphones that the speaker might commonly use in different situations, such as:
- Hand-held mics - High quality mics usually attempt to isolate the diaphragm from vibrations using foam padding, suspension, or some other method. Low quality mics tend to transfer vibrations from the casing right into the diaphragm, resulting in a terrible noise.
- Lavalier mics - These are attached by a small clip to the clothing of the speaker, usually to collars or ties. The cord may be hidden by clothes and either run to a radio frequency transmitter or a digital audio recorder kept in a pocket or clipped to a belt (for mobile work), or directly to the mixer. These usually do not have protection from handling noise.
- Stationary mics - These are permanently attached to a podium. With an attached microphone, you are limited to the space immediately in front of the podium. Some stationary mics are in a holder on the podium, which can be removed to allow you to move around at least the length of the connecting cable.
Microphones can be placed in several different arrangements in the room for recording or videoconferencing, such as:
- In close - The microphone is placed relatively close, within three to twelve inches, which reduces extraneous noise.
- In distant or ambient miking - The microphone is placed at some distance from the speaker. The goal is to get a broader, natural mix of the sound source, along with ambient sound, including reverberation from the room or hall.
- In room miking - This is used together with a close microphone, sometimes during the speaker Q&A.
To make the most out of a microphone, a speaker should consider these techniques:
- Hold the microphone about six to eight inches from your mouth and speak over the microphone.
- Make sure you have the right microphone for speaking. Don't just use whatever mic is at hand.
- Note that lavalier mics do not usually have protection from handling noise. It is therefore important to make sure they will not be moved or bumped.
- Conduct a sound check with any microphone. Make sure to test with the speakers in the actual room.