Communication Theories - Soundscape Ecology: Principles, Patterns, Methods and Applications - page 62

4.1 Introduction

Communication is an important component of animal life, and in particular com-
munication mediates reproduction and survival, as stressed in the introductory
remarks of the topic Animal Communication Networks by McGregor ( 2005 ).
Communication is a process between a signaler and a receiver in which information
in the form of structured energy transients between the two sides. Communication
represents a semiotic strategy used by a sender to contact a receiver via a semetic
relationship (sensu Hoffmeyer 2008 ). However, this dyadic vision is overpassed by
the reality of groups of individuals that simultaneously exchange information. In
this way, a communication network is created and maintained in a specific space
and for some time. The network model of communication seems to have more
reasons to exist because the reality often is not confined to a couple of contenders
but includes also a multitude of individuals sparsely located in the foreground
where they are waiting to enter into the action. Such individuals can use an
eavesdropping-like strategy to grasp some of the transient information between a
transmitter and a receiver.
To communicate means to connect a source with a receiver, and this depends on
the energy with which a signal is emitted and by the environmental conditions
through which such signals pass (Forrest 1994 ). Attenuation and degradation are
common effects that modify the signal that passes through a physical medium (air,
water, soil, biological tissues) and a biological codification and decodification. It
has been demonstrated that the environmental modification of an acoustic signal
largely depends on the frequency at which the signal is emitted but also on the
fluctuation of amplitude and reverberations. For instance, spherical spread, absorp-
tion, refraction, reflection, and diffraction are phenomena associated with sound
transmission through the atmosphere that are relevant in the communication pro-
cess (Wiley and Richards 1978 ).
We distinguish between broadcast information and received information. The
information at the source is greater than the information at the receiver. The
broadcast information depends on the signal that is produced; the received infor-
mation depends on the capacity of the receiver to decode the signal and to interpret
such signal for its purposes.
Noise is a property of the communication channel, and such noise contributes to
decoding the signal by the receiver. Errors can occur in the transmission of the
signal but also at the reception. At the receiver, errors may be of two types: an error
in discriminating between a perturbation and a real signal and an error in not
distinguishing variation in signals. The two errors are connected. For instance,
random degradation of a signal during the transmission increases the second error.
The capacity to discriminate relevant variations in signals decreases with the
distance between source and receiver.