Week 5: Cherry's Chapter 4

Reading Questions, by Zach Tomaszewski

for CIS 702, Fall 2004, taught by Dr. Martha Crosby

1. Cherry talks about 2 classes of measurement of sound - the "measurement of physical signals" and the "observation and comparisons made of the sensations" (p.125). After discussing the importance of context in human communication, is it appropriate to study these out of context?

Cherry stresses that the difference between physical sounds and the sensations caused by those sounds is a difference between objective and subjective experience. For Cherry, physical signals, such as sound and light waves, can be measure objectively. With an accurate measuring tool or machine, the results of such measurements will be consistent in terms of frequency and intensity. On the other hand, sensations can vary between people and between situations. When a person describes the pitch or loudness of a sound, it is a reported experience not easily reproduced by another.

On this point, Cherry claims that we cannot (or at least should not) measure sensations unless the "measurer" is a participant in the study. That is, if the point of the study is to determine the effects of physical sounds on subjective sensations, a "measure" of these sensations might be interesting. But otherwise subjective measures are of little use for Cherry. He claims that they cannot even be measured in the true sense of the word. Instead, different sensation experiences can simply be placed in rank order compared to each other. I disagree that people cannot have their own internal measuring scales. However, I do concede that such measurements would not "constitute objective measurement against some external physical scale" (p. 125).

Certainly, sensations of the same physical signal can vary according to the context of the experience. For instance, when listening to music through a pair of headphones on an airplane, the music may seem normal or even quiet. However, upon getting off the airplane and resuming the music at the same volume settings, the listener may find that now the music is surprisingly loud.

In such a situation, where signals can be measured consistently and objectively while sensation "measures" vary widely by listener and context, should we base our study of communication upon the physical? Should we ignore the subjective, contextual elements in order to discover objective truths? I think not. For during communication, it is precisely the communicators' subjective sensations and experiences that are the most important. Even when limiting ourselves to questions of signals and sensations (and so ignoring meaning or syntax or the information transmitted), we see that it is still the sensation that affects the communication the most. What is important is the listener can hear me, not that I speak at a consistent, standard decibel level. If two people hold a conversation in a subway station, they will need to raise their voices when a subway train goes by. Consistency of the physical vocal signals is not enough; we need to adapt to the sensations as well.

2. On page 159, Cherry discusses intelligibility and how different types of communication channels may be used under different conditions. With the increasing number of channels at our disposal, how do we choose the best medium?

Intelligibility is essentially the level to which your transmitted message can be understood by the receiver.

Intelligibility is affected by a number of factors. Learning the idiosyncrasies of an individual speaker can be important. For instance, if a speaker says "Come see me whenever you're free" when he means "See me right away", the intelligibility of his messages will improve as you learn what his phrases mean. On a less conscious level, we adapt to people's accents. Their messages become more intelligible as we get used to how they say their words.

The context of past experiences we have, or the environmental context we share with the speaker right now, provides support for many messages. Often, cryptic references to past experiences are enough to cause laugher or reminiscence with old friends. If a speaker refers to a current event as a example or as the source of an analogy, her message can become unintelligible if we are not aware of that event. The situational context can also shade message meanings, such as in terms of sarcasm, irony, or double meanings.

Redundancy is also important. You must be able to decipher the words the speaker is sending, as well as discern the gist of her message if you miss a few words.

There is now a great variety of communication channels--TV, web pages, email, instant messaging, cell phones, etc. Yet often times we find that some of these media don't provide messages as clear as those in face-to-face meetings. Thus, despite all these other channels, people often have to meet and sit down together to clarify important messages.

One of the most frequent failings of modern communication channels is that they offers limited redundancy. There are no nonverbal cues to support the message. Often there is little or very delayed feedback, which means the sender gets less chance to tune their messages, perhaps adding more information where the original message was not rich or redundant enough.

Additionally, as modern communication channels cross the globe, and we can form new relationships with people we've never physically met, we can lack a lot of context. Our backgrounds and cultural contexts may be different, and the significance of our local events may vary. (A civil war is very significant to a person living in that country, but may only be back page news for someone on the other side of the world.) Precisely when we need to be able to transmit more information to fill in these gaps or discrepancies in context, we often find ourselves using channels like email, where the "bandwidth" is quite limited.

I think we will continue to choose the best medium based on cost, convenience, and effectiveness. Though face-to-face meetings may be the most effective, they are not cheap or convenient for two people on opposite sides of the globe. However, when those two people are working on an important project, often it becomes necessary. Also, as we have more channels available to us, we may be able to use multiple channels over time while communicating with the same person. This may help fill in some of the gaps of each individual channel.

3. Do you agree with Cherry, on page 127, "It is an event, and our ears are sensitive and discriminatory not only toward pitches but also toward the timing of events."? Please state your reasons.

Cherry points out that our experience of the frequency and intensity of sound waves leads to our sensations of pitch and loudness. But he holds that our experience of these sensations over time is as important as the sensations themselves. I agree that we do pay attention to the timing of our sensory experiences, such as sounds.

First of all, the same series of pitches, if compressed into less time or dragged out to the extreme makes them unintelligible. For example, if a 30-second sound recording is played back in 15 seconds or over 2 minutes, it may become harder to understand, possibly even the point of becoming unintelligible. As Cherry points out, if the duration of a sound is compressed to 20 microseconds or less, the sensation of any pitch at all diminishes until the sound seems only to be a click (p.126). So it seems that in order to experience a sound, it must be over time.

Even as the experience of an individual pitch or phoneme requires some time, experience of a string of them also requires time. For example, if the phonemes that make up a word were all played in the same moment, rather than sequentially, the word would likely be unintelligible. Even though all the same information is being transmitted, it is not be sent over a suitable period of time.

Similarly, our experience of time is unidirectional. As in the example above, were the recorded word played backwards, it quickly becomes unintelligible, even though all the same phonemes and pitches are present.

While the pitch sets the tone of a message, speed also sends contextual clues about the message. When people talk faster, it affects the message by placing it in the context of urgency or excitement.

So, based on this evidence--that the sensations of individual pitches takes time, that experience of the collection of sounds that make up a word must also occur over time and in the correct temporal order, and that the speed of a speaker can affect the context of the message--I would agree that the experience of time is as important as the experience of pitch in understanding the sensation of sound.

Cherry, Colin. On human communication: a review, a survey, and a criticism. Cambridge: Technology Press of Massachusetts Institute of Technology, 1957.