Language Sample Collection
The collection of language samples is a foundational element of AAC evidence-based practice. Language activity monitoring (LAM) makes this a feasible task. Click AAC clinician perspective on the value of language sample collection to learn more.
(As with all language sample collection for clinical practice or research, informed consent must be obtained.)
Language Activity Monitoring (LAM)
Language activity monitoring (LAM) is the automatic recording of the content and time of language events generated using AAC systems. Language samples can then be analyzed for the support of AAC evidence-based practice. The primary LAM implementations are 1) as a built-in feature in modern AAC systems and 2) as software to allow a PC to act as a LAM (U-LAM). References on LAM are available elsewhere on the AAC Institute web site.
LAM data consists of two required fields and one optional field. For each language event, a time stamp and the content are available. Analysis of a language sample containing this information yields much information of clinical significance. The optional field is a three letter mnemonic indicating how the language event was generated in the AAC system. It has been found that the method used to generate language can have a dramatic impact on communication performance. This optional field provides information that addresses this issue.
The LAM file can start with a header. The header may include components such as the name and version of the AAC system and a privacy notice. An example is presented here:
### CAUTION ###
The following data represents personal communication.
Please respect privacy accordingly.
Language Activity Monitor "device name"
Version 2.00 07/26/01
ACME AAC Company
09:27:17 OWS "I "
09:27:19 OWS "am "
09:27:22 SMP "hungry "
09:27:24 OWS "and "
09:27:26 OWS "I "
09:27:29 SMP "want "
09:27:34 SPE "s"
09:27:36 SPE "o"
09:27:38 SPE "m"
09:27:43 WPR "some "
09:27:49 DWP "something "
09:27:51 OWS "to "
09:27:58 PAG "eat "
Modern AAC systems include LAM or an alternative logfile function as a standard built-in feature. In this case, the AAC system manual explains how to turn on the LAM and how to send the LAM data to the computer for viewing and/or analysis. AAC systems that include LAM or an alternative logfile function are available from the following manufacturers:
Prentke Romich Company
Reading the LAM file from a Pathfinder memory card
In addition to the traditional use of the serial cable connection (the same cable used for computer access and Memory Transfer Interface (MTI)), the LAM data can be retrieved from a PRC Pathfinder using the following method:
1) Remove the flash memory card from the Pathfinder and connect it to the computer using a card reader. (Card readers are readily available and some printers include this function.)
2) Under My Computer, open the flash memory card (shown as Removable Disk), and then open the "voc" folder. The LAM file is "DATA.LOG". Copy this file and paste it where you want to access it later. It is a test (.txt) file and can be opened using notepad, Word, etc.
To open with PeRT, add the file extension ".txt" to the file name (DATA.LOG.txt). This is also a good time to change the file name to include other information that will help keep things well organized. The recommended file name format is:
- "YYMMDD" is year, month and date when the language sample was collected.
- "n" is an integer, usually 1, used to designate which language sampe this is for the day.
- "ls" is two letters used to designate the language sample collection protocol that was used.
co Conversation in Interview pd Picture description sr Story retelling ta Therapy activities
- "name" is the last name of the person.
Older AAC systems do not have LAM built in but some have a serial port text representation of what is spoken using the system. In this case, U-LAM (Universal Language Activity Monitor) software allows a PC to monitor the serial port and records both the time and content of each event. The AAC system must be configured so that language events are sent out the serial port as they are generated. Click on the following AAC system manufacturers to obtain instructions on how to configure their products for use with U-LAM serial port monitoring.
Prentke Romich Company
When an AAC system has neither built-in LAM nor a serial port text representation of language events, it is still possible to collect a language sample from an AAC system with speech output. The U-LAM program has an audio recording feature that allows audio events to be recorded and time-stamped in a PC. A microphone is connected to the computer and positioned near the speaker of the AAC system. Each time something is spoken using the AAC system, U-LAM records a .wav file plus the computer clock time. While this method requires transcription of the spoken language events into text, it does result in LAM file data to support evidence-based practice.