Phone Recording Enhancement & Tips for better recordings
Apr 25, 2016 at 04:36PM A popular source of recordings that we are asked to analyse or enhance are mobile phone recordings. Due to the convenience of mobiles being close onhand they are often used to record situations that are later needed to be enhanced or are used to try and resolve disputes. They are similar in nature to digital dictation recorders and are not always ideal.
We always go through an assessment process with these types of recordings because the problems can be of various types and each individual case is different. Luckily the file sizes are generally small enough to be easily sent to us electronically for the assessment process.
Due to the nature of mobile phones we find a number of different problems. Like dictation devices the microphones are omnidirectional, that means they pick up audio from all around. This can be both an advantage and disadvantage, but in recording circumstances it means that a lot of unwanterd audio can be picked up including background traffic noise, airconditioners and other people as the mic is not picking up only the specific wanted audio.
Some phones also have automatic level controls which try and bring up the voice when it goes quieter, This can result in increased backround sounds making the wanted sounds harder to hear.
Interference problems such as clicks, thumps. pops. outdoor wind noises, mains power noise and hums, lighting buzzes and other technical problems will also affect the intelligibility of the audio. (many of these issues are worse on the older style micro cassette recorders) At times when recorders are hidden in clothing the fabric will rub directly on the microhphone causing a great deal of unwanted noise
Another common issue we find is that the device can be placed a long way from the source of the sound, in an adjacent room, down a hall way, in the back of a car, or in a cupboard hidden from sight. Again this makes the required audio very low in comparison to other sounds (which are often not focussed on at the time). Another problem is introduced which is the compression algorythymn that the audio is recorded with by the phone. (typically low resolution mp3s or m4a formats) Often these have artifacts at low volume levels and these can even be misinterpreted as people talking at a very quiet level. Also increasing the distance from the source will reduce the treble in the voice, again making the diction less easily understood and improving the quality even harder.
The final area of recording problems is where the sound source or other sounds in the location are distorting the microphone on the device or the volume of the recording has been turned up too loud causing the audio to be heavily distorted. Distortion is difficult to remove although in many instances it can be reduced significantly.
All of the above problems with recordings can be addressed and often improved signicantly. To get the best results a number of different processes are often used and this is where the time can come in to an enhancement project. Simply raising the volume will not give the best result and may not be possibly if the volume already "peaks" at 0dB.
Unwanted background sounds that are unheard at low levels will be brought up along with the rest of the audio . Hums. buzzes and random clicks and pops may also prevent the audio from simply being brought up in volume (these may all have to be addressed individually)
If you have a recording with any of the above issues then contact us for details of the assessment process where we'll be able to give you an idea of what we can do to improve the quality of your recording.
if you are trying to record on your mobile device some of the following tips will help to improve the quality of the end result.
1/ Try to balance the voices in recording by finding a suitable place to put the recorder that is equidistant from both talkers.
2/ If you can control the environment where the recording is taking place. Turn off any loud sources of sound, including, TVs, Radios, Airconditioners or motors such as in a vehicle.
3/ Try a programme such as Rode's RodeRec app for Iphones that bypasses the codec in the phone and produces a much higher quality recording.
4/ Try not to cover the phone with anything that will affect the recording quality.
5/ Try not to hold the phone or place it in a pocket or bag while recording.
6/ Set up the recorder in advance and check the level settings.
7/ Try to avoid outdoor recordings where you have no control over random sounds such as cafes, restaurants, vehicles or wind.
Don't forget you can contact us at [email protected] for further information on our audio enhancement services.