For week 4 and 5 we have been looking into sound.  Sound has come across as a more fundamental and important element to film and video production than I could ever have imagined.  Microphones are everywhere.  Picking up sound for your favourite television show to letting you speak to your friends over the phone.

Our reading this week was from “Making media: foundations of sound and image production,” by Jan Roberts-Breslin.  This reading covers all the nitty-gritty technicalities of sound, including:

• sound waves- where the ‘crest’ equals the maximum amount of pressure in a sound wave and the ‘trough’ of the wave equates the release of pressure
• Wavelength- the vibration of air pressure of a sound wave
• Frequency- which is the amount of cycles that a sound wave can move through in 1 second.  Frequency also determines the pitch of a sound wave
• Amplitude- being the height of a sound wave.  It is measured by ‘decibels’

Roberts-Breslin goes on to introduce microphones to the equation.  Man-made technology to increase the decibels and make recording possible.  I am no foreigner when it comes to microphones as I have a background in singing and studying music, however the technicalities surrounding a microphone and actually using one are two different things.  In our workshop in week 4, we used a ‘zoom’ microphone to test out our skills and get a feeling of recording potentially for the first time.  It was quite interesting to hear the power the little microphone generated.  Being a 360 degree microphone, it picked up sound from all corners of Melbourne.  It was quite difficult to find an area which was quiet enough to record a ‘formal interview,’ but we finally opted for a stairwell inside building 80.

There are many different types of microphone available and choosing the right one requires thought on what you want to record.  Most common microphones will be either dynamic or condenser.  A dynamic microphone works with magnetism where a metal coil is positioned near a magnet which creates a magnetic field.  The coil moves as it receives sound vibrations creating electric energy (voltage) which then stores the information (frequency and amplitude) of the sound.  Condenser microphones (capacitor mics) contain a positive charged plate and a negative charged plate- one moving and one fixed.  Due to the plates being so close, the negative and positive charges create voltage.   The moving plate moves towards the negative plate and the closer it gets the higher the voltage.  Condenser microphones create small amounts of voltage so amplification is necessary.

Condenser microphones tend to be quite fragile and can be sensitive to interference as well as needing to be pre-amplified, therefore they are a good option for studio recording or music reproduction.  Whereas dynamic microphones are built to withstand being knocked around thus making them perfect for recording in the field.

So, right now we are only seeing the tip of the ice berg in terms of microphones and technicalities surrounding them.  There is a world of information regarding directional (omnidirectional, bidirectional, unidirectional) microphones.

• Omnidirectional is sensitive to all sound (except for sound directly behind it)- good for overall (ambient) sound
•  Bidirectional is sensitive to two directions of sound
• Unidirectional (cardioid)- Sensitive to one direction of sound- although, they are susceptible to picking up surrounding sound- the on-axis range is at the front of the microphone where it is most clear and loud

It seems that information surrounding microphones is never-ending at this point, but through practical work I hope to be able to learn more as time goes on.